Specifications Hign-concerned Chemical:None Waterproof Grade:5ATM Model Number:R04 Activity Tracked:Activity Tracker,Steps Tracker,Distance Tracker,Calorie Tracker Metrics measured:Heart Rate Monitor,Sleep Monitor,Blood Oxygen Monitor,Stress Monitor Certification:ce,FCC Brand Name:Uhoofit Battery Capacity(mAh):15mAh (18mAh for size 9 and above) Basic Parameter Chipset: JL7073A APP: QRing Compatible System: For Android 5.1 and above, IOS 8.0 and above Memory Flash: RAM 284KB FLASH 8Mb BT: 5.4 Sensor: STK8321-W Heart Rate: HX 3918 Battery: 15mAh (18mAh for size 9 and above) Waterproof Level: 5ATM Major Function --Daily activities: Step count, distance, calorie calculation --Health management: heart rate measurement, blood oxygen saturation, HRV heart rate variability, stress, sleep tracking, multiple exercise modes --Other functions: remote control for taking photos, searching for rings, menstrual cycle Software Feature --Step count, sleep, heart rate, exercise data recording --Health monitoring, stress, blood oxygen measurement --Multiple sports modes, photography --Supported languages: Danish, Ukrainian, Russian, Croatian, Hungarian, Hindi, Indonesian, Trkiye, Hebrew, Greek, German, Italian, Latvian, Czech, Slovak, Slovenian, Japanese, French, Polish, Thai, Estonian, Swedish, Lithuanian, Simplified Chinese, Traditional Chinese, Romanian, English, Dutch, Portuguese, Spanish, Vietnamese, Arabic, Korean, Malay