Specifications Hign-concerned Chemical:None Waterproof Grade:5ATM Model Number:Smart Ring Display screen:No NFC Support:No Activity Tracked:Activity Tracker,Steps Tracker,Distance Tracker,Calorie Tracker Metrics measured:Heart Rate Monitor,Sleep Monitor,Blood Oxygen Monitor Item Weight:2.5g Case Material:STEEL Certification:ce,FCC Brand Name:Ola Esporte Battery Capacity(mAh):15mAh Size: 7# =Inner diameter 17.9mm, 8# = Inner diameter 18.3mm, 9# = Inner diameter 19.2mm, 10# = Inner diameter 20.0mm, 11# = Inner diameter 20.9mm, 12# = Inner diameter 21.6mm, 13# = Inner diameter 22.3mm Function: 1.Sports modes: Running, cycling, Ropeskipping, Walking, Mountaineering, yoga, Dance,golf. 2.Motion data: Accurate distance / accurate calorie data / accurate step count. 3.Heart rate: APP launches heart rate test / Dynamic rate trend and data analysis / Heart rate historical data. 4.Sleep: Precise sleep algorithm, sleep coach reminds. 5.Blood oxygen:APP initiated blood oxygen test / continuous blood oxygen data / historical blood oxygen data. 6.Camera control: The app's shake-to-take-photo feature. 7.Heart rate accuracy: The accuracy rate of static heart rate is more than 98%,(compared with the laboratory test of heart rate belt). 8.Others: Unit format, sedentary reminder, low power reminder, heart rate warning. Product Parameters: Name:Smart Ring Color: Black,Gold,Silver Size: 7.8.9.10.11.12.13 Battery capacity:15mAh Stanby Time:About 45days Working Time:About 3-5days Charing time:0.5H G Sensor:STK8321 Heart Rate Sensor:GH3018 Waterproof Level:IP68 Charging Requirement:Charging 1A or less Notes: 1. After receiving the ring, please use the charging adapter to charge the ring for more than 2 hours. 2. Please scan the QR code of the manual to download the APP before use.