Fangrui Product Details 1. R8 Size 18 Smart Ring, Support Heart Rate Blood Oxygen Sleep Multiple Sports Modes 2. About Product 3. Material: Ceramics+steel 4. Main Chip: Nordic Nrf52832-ciaa 5. Chip: Sy8602 6. Sensor: Qma6100p 7. Battery: 23mah,3.74.2v Lithium Battery 8. Sports Measure:calories, Steps, Mileage 9. Sleep Monitor: 20:00-8:00 10. Multi-sports Modes:running, Cycling, Skipping Rope, Fitness, Mountaineering, Yoga, Golf, Dance 11. Heart Rate Checking, Blood Pressure, Blood Oxygen, Fitness Track 12. Charging Mode:magnetic Charging Cable,case Charging 13. The App System Requires Android: 6.0 Or Above,ios: 11.0 Or Above 14. Bluetooth Version:5.2 15. Charging Voltage: 4.6-5.2v 16. App Name: Smarthealth 17. Dust Proof & Waterproof Level: Ipx8 18. App Language: English,simplified Chinese,chinese Traditional,russian,ukrainian,german,french,italian,spanish,portuguese,polish,greek,romanian,hungarian,turkish,czech,slovak,irish,croatian,swedish,danish,finnish,arabic,hebrew,persian,norwegian,japanese,korean,thai,vietnamese 19. Size 18: Outer Diameter 24.5mm; Inner Diameter 17.8mm 20. Packing List: 21. Smart Ring X1 22. Charging Case X1 23. User Manual X1