Oura Ring 4 Smart Ring – Silver, Size 9

Product Overview

Oura Ring 4 is a screenless smart ring designed to collect biometric and activity data throughout the day and night. The configuration associated with ASIN B0D9WWB3WX is the Silver finish in Size 9. Oura Ring 4 uses an all-titanium design with recessed internal sensors, replacing the raised sensor bumps used by earlier generations.

The ring measures approximately 7.9 mm wide and 2.88 mm thick. Oura Ring 4 models weigh approximately 3.3 to 5.2 grams depending on ring size. The device combines optical sensors, temperature sensing, and an accelerometer to measure metrics used for sleep, activity, readiness, heart-rate, respiratory, stress, and temperature-trend insights.

Oura specifies typical battery life of approximately five to eight days, depending on ring size, settings, enabled features, battery age, and usage. Charging normally takes about 20 to 80 minutes. The ring is water resistant to 100 meters and communicates with the Oura mobile application through Bluetooth. The Oura App supports compatible iOS and Android smartphones. Full access to detailed Oura insights requires an active Oura Membership, while limited information remains available without an active membership.

Product Information

Identification

Physical

Product Identifier Summary

Oura Ring 4 is produced in multiple finishes and ring sizes. The finish, size, generation, and barcode should therefore be considered together when identifying an exact configuration.

• Model Number: Oura Ring 4 identifies the fourth-generation hardware platform. Individual sizes and finishes can use additional inventory identifiers.
• MPN: A sufficiently verified manufacturer part number for this exact Silver Size 9 configuration is omitted rather than inferred from retailer inventory codes.
• UPC: A separate 12-digit UPC was not sufficiently verified for this exact configuration.
• EAN: EAN 6430060153417 is associated with the Oura Ring 4 Silver Size 9 configuration.
• GTIN: The verified 13-digit EAN functions as a GTIN-13 for trade-item identification.
• ASIN: B0D9WWB3WX identifies the catalog record associated with this Silver Size 9 configuration.
• ISBN: ISBN identifiers apply to books and certain publications and do not apply to wearable electronics.

Common Uses

Oura Ring 4 is designed for continuous wearable tracking rather than direct interaction through a screen. Data is synchronized to the Oura App for interpretation and presentation.

• Tracking sleep duration and sleep-stage estimates.
• Monitoring resting heart rate and heart-rate variability trends.
• Tracking daytime and nighttime heart-rate information.
• Recording movement and daily activity.
• Estimating readiness based on multiple physiological signals.
• Monitoring temperature trends.
• Tracking respiratory-rate trends during sleep.
• Monitoring blood-oxygen-related sleep measurements.
• Viewing daytime stress and resilience information.
• Recording automatically detected activities.
• Reviewing cardiovascular fitness-related estimates.
• Following menstrual-cycle and other supported women’s health insights.
• Synchronizing compatible data with third-party health and fitness platforms.

Maintenance & Care

The ring is designed for continuous wear, but routine cleaning helps keep the sensor area in contact with the skin and reduces buildup from soap, lotions, sweat, and other materials.

• Clean the ring with water and a small amount of mild dish soap when necessary.
• Rinse away soap residue after cleaning.
• Dry the ring and finger thoroughly before prolonged wear.
• Keep the recessed sensor area clean.
• Avoid abrasive cleaning materials that can scratch the exterior finish.
• Remove the ring during activities where heavy metal objects could scratch or crush it.
• Avoid wearing the ring when handling equipment that could trap or compress the finger.
• Keep the charging contacts and charging dock clean and dry.
• Charge the ring at normal room temperature.
• Keep the ring firmware and Oura App current.
• Expect minor cosmetic scratches to develop through normal contact with hard surfaces.

Safety Information

• Oura Ring contains a rechargeable lithium-polymer battery.
• Do not puncture, crush, open, burn, or modify the ring.
• Stop using the ring if it becomes abnormally hot, swollen, cracked, or physically damaged.
• Remove the ring if it causes persistent skin irritation or discomfort.
• Do not wear a ring that is excessively tight.
• Remove the ring during activities where it could become caught in machinery or heavy equipment.
• Water resistance does not mean the ring is suitable for scuba diving.
• Keep the charger and electrical connections dry.
• Do not place metallic objects between the ring and charging dock while charging.
• Oura-generated wellness information should not be treated as a substitute for professional medical diagnosis or emergency care.
• Individual health metrics can be affected by fit, movement, circulation, environmental conditions, and other factors.

Technical Specifications

Sensor System

Optical Sensors

Oura Ring 4 uses red, green, and infrared light to collect several biometric signals. Green and infrared sensing support heart-rate and heart-rate-variability measurements, while red and infrared sensing support blood-oxygen-related measurements during sleep.

Photodetectors

Three photodetectors receive light reflected through the finger. Oura’s Smart Sensing system selects usable signal paths as finger position and movement change.

Temperature Sensor

A digital temperature sensor tracks changes relative to the wearer’s established baseline. The ring is designed to emphasize temperature trends rather than functioning as a conventional handheld thermometer.

Accelerometer

The accelerometer tracks movement and supports daily activity, steps, sleep movement, and automatic activity-detection features.

Smart Sensing

Oura Ring 4 introduced a sensing architecture called Smart Sensing. The system is designed to account for differences in finger anatomy, ring position, and movement by selecting among available signal pathways.

The recessed-sensor design also removes the pronounced interior sensor bumps found in previous Oura Ring generations. This creates a smoother internal surface while maintaining optical and temperature sensing.

Sleep Tracking

The ring collects overnight movement and biometric information that is processed into sleep-related estimates and an overall Sleep Score. Detailed sleep information requires synchronization with the Oura App and access to applicable software features.

• Total sleep estimates.
• Time in bed.
• Sleep-stage estimates.
• Sleep timing.
• Resting heart rate.
• Heart-rate variability.
• Respiratory rate.
• Temperature deviation.
• Blood-oxygen-related measurements.
• Sleep regularity and timing information.

Readiness Tracking

The Readiness Score combines multiple signals to provide a summary of how recovered the user’s body appears relative to established personal patterns. Inputs can include sleep, recent activity, resting heart rate, heart-rate variability, temperature trends, and other factors.

Readiness is an algorithmic wellness score rather than a medical diagnosis. Individual scores should be interpreted as part of longer-term trends rather than as definitive evidence of health or illness.

Activity Tracking

Oura Ring 4 tracks movement throughout the day and can automatically identify selected activities. Activity information contributes to daily activity goals and the Activity Score.

• Daily movement.
• Step estimates.
• Activity duration.
• Automatic Activity Detection.
• Activity heart rate for supported workouts.
• Dynamic activity goals.
• Inactive-time tracking.

Heart and Cardiovascular Metrics

The optical sensor system records heart-related information during daytime, nighttime, and supported activity periods. Available software can convert these measurements into several trend-based insights.

• Resting heart rate.
• Daytime heart rate.
• Nighttime heart rate.
• Heart-rate variability.
• Cardio Capacity estimates.
• Cardiovascular Age insights.

Blood Oxygen Sensing

Red and infrared optical sensors support blood oxygen sensing during sleep. The resulting measurements are used within supported overnight breathing and oxygen-saturation insights.

Enabling blood oxygen sensing can reduce battery life. Oura notes that battery duration can be shorter when this feature remains continuously enabled.

Temperature Trends

The ring tracks changes in skin temperature relative to a personalized baseline. Temperature information contributes to several Oura features, including readiness and supported cycle-related insights.

The temperature measurement should not be interpreted as equivalent to a clinical oral, rectal, ear, or forehead thermometer reading.

Stress and Resilience

Supported Oura software evaluates daytime physiological information to estimate periods associated with stress and recovery. Resilience features use longer-term patterns to summarize how the body appears to balance physiological stress with recovery.

These scores are wellness-oriented interpretations generated from wearable data and do not independently identify the cause of stress or establish a medical condition.

Women’s Health Features

Oura Ring 4 supports software features related to menstrual-cycle patterns and pregnancy insights in supported regions. These functions use ring data and information provided through the Oura App.

Feature availability can vary by region, account, software version, and regulatory status. Wearable estimates should not replace professional medical testing or clinical care.

Battery and Charging

Oura currently describes Ring 4 battery life as typically five to eight days. Actual runtime is affected by ring size, battery age, enabled features, automatic activity detection, blood oxygen sensing, and overall usage.

Larger ring sizes can contain slightly larger batteries than smaller sizes. Oura also notes that frequent blood oxygen sensing and extended activity-heart-rate recording can shorten time between charges.

• Typical battery duration is approximately 5–8 days.
• Charging normally takes approximately 20–80 minutes.
• The charging dock must match the ring size.
• Short partial charging sessions are supported.
• Lithium-polymer battery capacity gradually declines with age and charging cycles.

Water Resistance

Oura Ring 4 is rated water resistant to 100 meters, or approximately 328 feet. The rating supports ordinary water exposure and many surface-water activities.

• Can be worn in the shower.
• Can be worn while swimming under suitable conditions.
• Can be worn in a sauna according to manufacturer guidance.
• Can be worn in hot tubs under appropriate conditions.
• Not designed for scuba diving.

Water resistance can be affected by physical damage, aging, and conditions outside standardized testing.

Oura Membership

An Oura Membership provides access to detailed measurements, trends, analysis, and personalized guidance within the Oura App. Membership is linked to the user’s Oura account rather than permanently to one physical ring.

Without an active membership, the Oura App provides a more limited set of information. This includes the three primary daily scores for Sleep, Activity, and Readiness, ring battery information, profile information, settings, and selected Explore content.

Product History

Oura began developing wearable rings during the 2010s and released successive hardware generations focused on sleep, recovery, activity, and physiological trend tracking.

Oura Ring Generation 3 was introduced in 2021 and expanded the platform with daytime heart-rate tracking, blood oxygen sensing, advanced temperature monitoring, and additional software features.

Oura Ring 4 was introduced in October 2024. The fourth generation adopted an all-titanium design, recessed sensors, a wider size range, Smart Sensing technology, and longer advertised battery life than the previous generation.

Oura subsequently introduced Oura Ring 5 in 2026. Oura Ring 4 remains a distinct fourth-generation platform, and its charger and sizing system should not automatically be treated as interchangeable with later ring generations.

Key Features

• Fourth-generation Oura smart ring.
• Silver titanium construction.
• Size 9 configuration.
• Seamless titanium interior.
• Recessed sensing components.
• Smart Sensing technology.
• Red, green, and infrared optical sensing.
• Three photodetectors.
• Digital temperature sensing.
• Accelerometer-based movement tracking.
• Sleep tracking.
• Readiness scoring.
• Activity scoring.
• Daytime and nighttime heart-rate tracking.
• Heart-rate variability tracking.
• Blood oxygen sensing.
• Respiratory-rate tracking.
• Daytime stress insights.
• Cardiovascular health-related insights.
• Supported women’s health features.
• Typical battery life of approximately five to eight days.
• 100-meter water resistance.
• iOS and Android application compatibility.

Package Contents

• Oura Ring 4 in Silver, Size 9.
• Size 9 Oura Ring 4 charging dock.
• USB-C charging cable.

Compatibility

Oura Ring 4 requires a compatible smartphone for setup, synchronization, firmware management, and viewing detailed data.

• Compatible with supported iPhones running iOS 16 or later.
• Compatible with Android devices running Android 11 or later with Google Play services.
• Requires Bluetooth 5.0 support on the paired smartphone.
• Uses the Oura App for setup and data analysis.
• Supports Apple Health integration under applicable account and membership conditions.
• Supports Health Connect integration on compatible Android devices.
• Supports selected third-party health and fitness application integrations.
• Requires a Size 9 Oura Ring 4 charger.
• Oura Ring Generation 3 chargers are not interchangeable with Oura Ring 4 chargers.
• Later-generation sizing and charging accessories should not be assumed compatible.

Frequently Asked Questions

What product is B0D9WWB3WX?

B0D9WWB3WX identifies an Oura Ring 4 smart ring in Silver, Size 9.

What generation is this ring?

It is the fourth-generation Oura Ring platform introduced in 2024.

What color is B0D9WWB3WX?

The exact configuration is Silver.

What size is B0D9WWB3WX?

The exact configuration is Oura Ring Size 9.

What is the EAN?

The verified EAN associated with the Silver Size 9 configuration is 6430060153417.

What material is Oura Ring 4 made from?

The standard Oura Ring 4 uses titanium on both its interior and exterior surfaces.

Is the inside of Oura Ring 4 plastic?

No. Oura Ring 4 uses a titanium interior.

Does Oura Ring 4 have sensor bumps inside?

No. The fourth-generation design moved its sensors into recessed areas, creating a smoother interior surface than Generation 3.

How wide is Oura Ring 4?

It measures 7.9 mm wide.

How thick is the ring?

The documented thickness is approximately 2.88 mm.

How much does Oura Ring 4 weigh?

Oura lists approximately 3.3 to 5.2 grams across the available Ring 4 sizes. Exact weight varies by ring size.

Does Oura publish an exact weight for Size 9?

Oura primarily publishes a weight range across Ring 4 sizes rather than a separate official weight for every individual size.

What sizes are available?

Oura Ring 4 is available in sizes 4 through 15.

Are Oura Ring 4 sizes the same as ordinary jewelry sizes?

Oura advises using its generation-specific sizing system because smart-ring fit can differ from conventional jewelry sizing.

Should the Oura sizing kit be used?

Using the correct Oura Ring 4 sizing system helps determine a fit that maintains sensor contact without excessive pressure.

Can an Oura Ring Gen3 size be assumed for Ring 4?

No. Changes in interior design can result in a different suitable size between generations.

Which finger should be used?

Oura commonly recommends the index finger for strong signal quality, although the middle or ring finger can also be used when fit and comfort are appropriate.

How tight should the ring fit?

The ring should remain secure against the skin without creating persistent discomfort or restricting circulation.

Can the ring rotate on the finger?

Small movement can occur during normal wear. Smart Sensing is designed to improve measurement reliability across changes in ring orientation and finger characteristics.

What sensors are in Oura Ring 4?

The ring contains optical LEDs and photodetectors, a digital temperature sensor, and an accelerometer.

What do the green LEDs measure?

Green and infrared sensing contributes to heart-rate and heart-rate-variability measurements.

What do the red LEDs measure?

Red and infrared sensing supports blood-oxygen-related measurements during sleep.

Does it measure heart rate?

Yes. Oura Ring 4 supports daytime, nighttime, and compatible activity heart-rate tracking.

Does it measure heart-rate variability?

Yes. Heart-rate variability is one of the measurements used in several Oura recovery and readiness insights.

Does it measure blood oxygen?

Yes. Blood Oxygen Sensing is supported during sleep.

Does it measure respiratory rate?

Yes. Respiratory-rate information is part of the supported nighttime measurements.

Does it measure temperature?

Yes. It tracks skin-temperature trends relative to an established personal baseline.

Is Oura Ring a medical thermometer?

No. Temperature trends from the ring should not be interpreted as direct clinical body-temperature readings from a conventional medical thermometer.

Does Oura Ring track sleep?

Yes. Sleep analysis is a central function of the Oura platform.

Can it estimate sleep stages?

Yes. Oura software provides estimates of sleep stages based on sensor data and algorithms.

Does it track naps?

Supported Oura software can identify qualifying sleep periods and naps under applicable detection conditions.

What is the Sleep Score?

The Sleep Score summarizes several overnight measurements and sleep-pattern factors into a daily score.

What is the Readiness Score?

The Readiness Score combines recent sleep, recovery, activity, heart-rate, heart-rate-variability, temperature, and other information to summarize recovery-related patterns.

What is the Activity Score?

The Activity Score summarizes daily movement, activity goals, inactivity, recovery balance, and related factors.

Does the ring count steps?

Yes. Movement data is used to estimate daily steps.

Does Oura Ring contain GPS?

No standalone GPS receiver is documented inside Oura Ring 4. Location-dependent activity features can use a paired smartphone when supported.

Does it have a screen?

No. Oura Ring 4 is a screenless wearable.

Does it vibrate?

No vibration motor is documented in Oura Ring 4.

Does it make sounds?

No speaker or audible alert system is built into the ring.

Does it have buttons?

No conventional physical control buttons are built into the ring.

How long does the battery last?

Oura currently describes typical Ring 4 battery life as approximately five to eight days, depending on settings, ring size, feature use, battery condition, and activity.

Why do some descriptions say up to eight days?

Eight days represents the upper end of Oura’s documented battery range under suitable conditions rather than guaranteed runtime for every user.

Does blood oxygen sensing affect battery life?

Yes. Continuous use of Blood Oxygen Sensing can reduce the time between charges.

How long does charging take?

Charging normally takes approximately 20 to 80 minutes depending on the starting battery level.

Can the ring be partially charged?

Yes. Short charging sessions can be used instead of always waiting for the battery to reach a very low level.

How is Oura Ring 4 charged?

The ring sits on a dedicated charging dock matched to its ring size.

Does Size 9 require a Size 9 charger?

Yes. The charging dock must correspond to the ring size.

Can a Gen3 charger be used?

No. Oura Ring 4 uses a redesigned charging system that is not interchangeable with Generation 3 chargers.

Is Oura Ring 4 waterproof?

Oura specifies 100-meter water resistance. Water resistance should not be interpreted as unlimited protection under every condition.

Can it be worn while showering?

Yes. Normal shower use is supported.

Can it be worn while swimming?

Yes. Swimming is within the documented water-use guidance when the ring is otherwise undamaged.

Can it be worn in a sauna?

Oura permits sauna use within its specified operating guidance.

Can it be worn in a hot tub?

Hot-tub use is included within Oura’s general water-use guidance, subject to appropriate temperature and product condition.

Can it be used while scuba diving?

No. The ring is not designed for scuba diving.

Does Oura Ring 4 require a phone?

A compatible smartphone is required for setup, synchronization, firmware updates, and viewing detailed measurements in the Oura App.

Does it work with an iPhone?

Yes. The Oura App currently supports compatible devices running iOS 16 or later.

Does it work with Android phones?

Yes. Supported Android devices require Android 11 or later with Google Play services.

What Bluetooth version does the phone need?

The paired smartphone must support Bluetooth 5.0.

Does it work with Apple Health?

Yes. Apple Health integration is supported under applicable Oura account and membership conditions.

Does it work with Android Health Connect?

Yes. Health Connect integration is available on supported Android devices.

Does it work with Strava?

Oura supports integration with selected third-party fitness and health services, including Strava.

Is an Oura Membership required?

The ring can provide limited information without an active membership, but detailed measurements, trends, and personalized insights require an active Oura Membership.

What information remains without membership?

Oura currently provides the daily Sleep, Activity, and Readiness Scores, ring battery information, profile information, settings, and selected Explore content without an active membership.

Does membership belong to the ring?

No. Oura Membership is associated with the user’s Oura account.

Can a different Oura Ring use the same membership?

Compatible replacement or additional rings can use the membership associated with the same account, subject to Oura’s current account features.

Can more than one ring be connected?

Oura supports multi-ring functionality for Oura Ring 4 or later with an active membership on supported iOS and Android devices.

Does the ring store data without the phone nearby?

Yes. Oura Ring 4 can store recorded data temporarily and synchronize it when the paired phone becomes available.

How much offline data can Oura Ring 4 store?

Oura documents up to approximately one week of onboard data storage for Ring 4.

Does it work without internet access?

The ring can collect data without a continuous internet connection, but synchronization, cloud processing, account functions, and some application features require connectivity.

Does it have a monthly subscription?

Oura Membership is available through recurring membership plans. Membership terms can change over time and should be checked through the Oura App or current account documentation.

Can Oura Ring diagnose medical conditions?

The ring provides measurements and wellness insights but should not independently be used to diagnose a disease or replace professional medical evaluation.

Can it detect illness?

Changes in temperature, heart rate, respiratory patterns, sleep, and other measurements can contribute to supported wellness features. These signals are not proof of a specific illness.

Can it track menstrual-cycle patterns?

Yes. Supported women’s health features can use temperature trends and user-provided information for cycle-related insights.

Can it track pregnancy information?

Oura provides pregnancy-related insights in supported software and regions. These features do not replace prenatal medical care.

Does it measure blood pressure?

No standard continuous blood-pressure sensor is documented for Oura Ring 4.

Does it measure blood glucose directly?

No glucose sensor is built into Oura Ring 4. Metabolic-health integrations can use information from compatible external services or devices where supported.

Can it measure body fat?

No direct body-fat sensor is included.

Can it track workouts?

Yes. The ring supports automatic activity detection and activity heart-rate tracking for supported activities.

Is it designed for weightlifting?

The ring can record activity, but removing it during heavy barbell, dumbbell, kettlebell, or machinery use can reduce scratching, finger compression, and equipment-contact risks.

Can titanium scratch?

Yes. Titanium is durable, but the exterior finish can develop scratches through normal contact with hard or abrasive objects.

Can the Silver finish change appearance over time?

Normal wear can produce fine scratches, scuffs, and other cosmetic changes. These do not necessarily indicate a sensor or battery malfunction.

How should the sensors be cleaned?

The interior can be rinsed and gently cleaned with mild soap when needed, then thoroughly dried before continued wear or charging.

Can hand sanitizer damage the ring?

Occasional incidental contact may occur during ordinary wear, but repeatedly exposing wearable materials to strong chemicals can affect finishes over time. Cleaning residue from the ring is appropriate.

Does it contain nickel?

Oura describes its standard Ring 4 titanium construction as non-allergenic titanium. Individual sensitivities can still vary.

What should I do if skin irritation develops?

Remove the ring and allow the skin to recover. Persistent or significant irritation should be evaluated appropriately before resuming wear.

When was Oura Ring 4 introduced?

Oura introduced its fourth-generation ring in October 2024.

What came before Oura Ring 4?

Oura Ring Generation 3 was the previous major generation.

What came after Oura Ring 4?

Oura introduced Oura Ring 5 in 2026.

Is Oura Ring 4 the same as Oura Ring 5?

No. They are separate hardware generations with different physical dimensions, sensor layouts, sizing ranges, and accessories.

What warranty applies?

Eligible new Oura products are covered by a one-year limited manufacturer’s warranty from the original purchase date, subject to applicable terms and local consumer law.

Buying Considerations

Correct sizing is particularly important for smart rings because optical and temperature sensors rely on consistent contact with the finger. Oura Ring 4 uses its own sizing system, so a conventional jewelry size or an older Oura size should not automatically be assumed to fit identically.

• Confirm B0D9WWB3WX corresponds to Silver, Size 9.
• Confirm EAN 6430060153417 when matching the exact configuration.
• Use an Oura Ring 4 sizing method rather than relying only on conventional jewelry sizing.
• Remember that the Size 9 ring requires a corresponding Size 9 charging dock.
• Consider the recurring membership requirement for access to detailed insights.
• Battery life varies according to settings and enabled sensors.
• Frequent blood oxygen sensing can reduce battery duration.
• Remove the ring during activities that may crush, deeply scratch, or trap the finger.
• Expect cosmetic wear on the titanium finish during normal use.
• Verify smartphone operating-system compatibility before setup.
• Health and wellness scores are algorithmic interpretations and should not replace professional medical assessment.

Customer Feedback Summary

This section summarizes recurring themes in publicly available feedback about Oura Ring 4. These observations reflect user experiences and independent evaluations rather than verified product specifications.

Positive feedback commonly focuses on sleep and recovery tracking. Users frequently describe the screenless ring format as less distracting during sleep than a smartwatch and appreciate viewing overnight trends without wearing a larger wrist device.

The smoother interior is another recurring positive theme. Owners familiar with earlier Oura generations often report that eliminating the raised interior sensor bumps improves comfort, particularly during overnight wear.

Battery life is generally considered suitable for multi-day tracking. Real-world reports vary because blood oxygen sensing, activity tracking, ring size, battery age, and synchronization behavior affect how often charging is required.

The mobile application also receives favorable comments for organizing sleep, readiness, activity, stress, temperature, and cardiovascular information into trend-oriented summaries. Some users find the quantity of available metrics useful, while others consider extensive daily tracking more information than they need.

Common limitations include cosmetic scratching, especially when the titanium ring contacts weights, metal equipment, cookware, or hard surfaces. Fit is another recurring issue because finger size changes during the day and an incorrect size can affect both comfort and sensor contact.

The membership model is also a recurring criticism. Some users object to requiring an ongoing membership for detailed insights after obtaining the physical ring, while others consider the software analysis an important part of the overall product experience.

Related Products

• Oura Ring 4 Black.
• Oura Ring 4 Stealth.
• Oura Ring 4 Gold.
• Oura Ring 4 Rose Gold.
• Oura Ring 4 Brushed Silver.
• Oura Ring 4 Ceramic.
• Oura Ring 5.
• Oura Ring Generation 3.
• Oura Ring 4 Sizing Kit.
• Oura Ring 4 Size 9 charging dock.

Last Updated

August 11, 2026