The Ultimate Smart Ring for Fitness, Health, and Sleep Monitoring Multiple Sports for Men Women Gifts

Basic Parameter Bracelet size diameter (mm): Size8: 18.1mm, Size 9: 18.9mm, Size 10: 19.8mm, Size 11: 20.6mmWeight: 4.4gChipset: RF03APP: QRingCompatible System: Android 5.1 or above, IOS 8.0 or aboveFLASH memory: ROM512KBBT: 5.0 low power consumption BT ChipSensor: STK8321Heart Rate: Vcare VC30FBattery: 17mAh Polymer lithium-ion batteryCharging time: About 1 hourLife time: 5-7 days of use, 15 days on standbyWaterproof: IP68Appearance material: stainless steel Size Size 8: Dia=18.1mm; Perimeter=56.9mmSize 9: Dia=18.9mm; Perimeter=59.5mmSize 10: Dia=19.8mm; Perimeter=62.1mmSize 11: Dia=20.6mm; Perimeter=64.6mm*How to measure the size1.Please use non-elastic rope2.Pull up3.Levelling Major Function Steps, distance, calorie countingHeart rate, oxygen saturation, blood pressure, sleep tracking Software Feature Steps, sleep, heart rate, workout data loggingHealth monitoring, blood pressure measurement, blood oxygen measurementMultiple exercise modes, photo remote control--APP supporte