RingConn Gen 1, Smart Ring for Women/Men, No App Subscription, Size First with Sizing Kit, Smart Ring Health Tracker, 7-Day Battery Life, Fitness & Sleep Tracker for iOS & Android (Black, Size 8)

RingConn Smart Ring, No App Subscription, Size First with Sizing Kit, 7-Day Battery Life Activity & Sleep Tracker/Stress/Heart Rate Monitor, Waterproof Compatible with iOS & Android(Black, Size 8)

Oura Ring Gen3 Sizing Kit-Size Before You Buy for Heritage and Horizon Rings-Measure Sizes 6-13 for Fit Before Purchasing, Sizes are Unique to Oura

Oura Gen3 Horizon Smart Ring - Size 8, Silver | Sleep, Heart Rate and Fitness Tracking Wearable - Up to 7 Day Battery Life - iOS/Android Compatible - Size First with Oura Sizing Kit