Hardware
Oura Ring 4 features a sleeker, fully titanium design and recessed sensors on the interior, enhancing both durability and wearability.
Oura Ring 4 is available in one design and six colors: Black, Silver, Stealth, Brushed Silver, Gold, and Rose Gold. It has an expanded size range, now available in sizes 4-15. We do not offer half sizes.
The sizing for Oura Ring 4 is slightly different from Oura Ring Gen3. If you’re switching between these different ring generations or uncertain about your size, make sure to use the right Oura Ring Sizing Kit for an accurate fit. The Oura Ring 4 Sizing Kit includes white ring sizers, and the Oura Ring Gen3 Sizing Kit includes black ring sizers.
For the best fit and most accurate readings, align your ring so that the sensors are against the palm side of your finger.
Sensors
Smart Sensing is a new sensing platform designed to give you the most complete picture of your health. The research-grade sensors work with an algorithm that adapts to the unique structure and skin tone of your finger and your current activity to deliver the most accurate, continuous data, day and night—all while optimizing battery life

Other Specifications
Battery: Up to 8 days. Battery life and longevity depend on Oura Ring size, Oura App settings, feature configuration, activity, battery age, usage, and many other factors; actual results will vary. Battery life and charge cycles vary by use and settings. Battery tests were conducted across various sizes and scenarios. See Ring Battery Tips for more information

Width: 7.9mm

Thickness: ~2.88mm

Weight: 3.3-5.2 grams (depending on ring size)