The Oura Ring 4 is an advanced health and fitness tracking smart ring featuring a premium gold titanium finish with physical vapor deposition coating. This Costco exclusive bundle includes the ring plus an additional charging plinth, providing two chargers total for convenient charging at home and travel.

The ring utilizes breakthrough Smart Sensing technology with 18-path multi-wavelength photoplethysmography sensors that dynamically adjust based on your physiology. Red and infrared LEDs measure blood oxygen levels during sleep, while green and infrared sensors track heart rate and heart rate variability 24/7, plus respiration rate during sleep. A digital temperature sensor monitors skin temperature variations for illness detection, cycle tracking, and recovery insights, while a 3D accelerometer captures movement, steps, exercise intensity, and nighttime restlessness throughout the day.

Advanced features include automatic detection of 40+ workout types, scientifically validated sleep staging algorithms benchmarked against polysomnography, and personalized Sleep, Activity, and Readiness Scores powered by machine learning. The recessed sensor design eliminates friction and pressure points for comfortable all-day wear. With up to 8 days of battery life, 100m water resistance, Bluetooth Low Energy connectivity, and data storage for up to two weeks, the ring works seamlessly with iOS and Android devices.

Available in size 9, measuring 7.90mm wide and 2.88mm thick, weighing between 3.3-5.2g depending on size. Includes first month of Oura Membership free, then $5.99/month to unlock all tracking features, guided meditations, and sleep stories in the Oura app.