O Ring Smart Ring, Fitness Trackers Rings with Sleep/Stress/Heart Rate/Women's Health Monitoring, No Subscription, Comfortable Wearing, Long Using, Fitness Ring for Android & iOS, Black-Size9

Order the Sizing Kit First The smart ring's sizing differs from standard jewelry rings. You must use the official sizing kit before purchase wear the tester ring to confirm comfort and accuracy. This step is essential to ensure reliable heart rate and HRV tracking. Innovative Stress Tracking The fitness tracker ring monitors HRV in the background 24 hours a day, automatically quantifies stress levels, and assists you in managing stress through personalized insights. Easily track your body's responses without interrupting your daily routine. Comprehensive Sleep Management The ring records and analyzes deep sleep, light sleep, REM, and wake duration in detail, providing core vital signs data such as sleep score, heart rate, blood oxygen, and HRV. It transforms complex sleep information into understandable scientific advice to help you manage your sleep. One Ring, Multiple Functions One fitness ring manages all your daily health management needs: step tracking, activity tracking, mood tracking, menstrual cycle prediction for women, basal body temperature monitoring, and more. Additionally, continuous performance improvements and new feature additions deliver a customized and evolving experience. No Subscription Fee All practical and fun features are free with the companion app. The ring ensures you can continuously experience real-time health tracking and personalized insights. Compatible with both iOS and Android