Amovan smart ring. Silver size 6. Model number AMR01. 💍Activity Fitness Tracker: The fitness tracking ring records exercise data and automatically monitors your heart rate and HRV every half hour, or you can do it manually via the app. Blood oxygen saturation and stress tests are measured manually via the app. 💍Sleep Tracker: The ring is your ideal health companion, our rings for men and women are both excellent choices. 💍No Subscription Fees: Smart Ring health tracker data can be easily viewed via a mobile app without subscription fees. Smart Ring supports Android 5.0 and iOS 10.0 and above systems. 💍Titanium Alloy Material: The smart ring is made of lightweight, skin-friendly and high-strength titanium, ensuring excellent workmanship and durability.