Main Functions: - Pedometer:Steps,Calories,Distance - Family Care - Heart Rate Monitor - Exercise Monitor - Remote Camera - Stress Assess/Female Physiological Cycle - Sleep Tracker Hardware: Bluetooth:5.4 Ring Battery:12-18mAh APP:LuckRing Standby Time:One full charge gives you(1-2 days of working time) iOS 12.0 or above,Android 9.0 or above Ring Material:Stainless Steel+Zircon Packaging Accessories Including: Smart Ring*1 Manual Charing Line*1 Ring Size: #6 (Ring inner diameter:16.85mm(0.66"),Ring circumference:2.01"-2.09") #7 (Ring inner diameter:17.5mm(0.69"),Ring circumference:2.13"-2.2") #8 (Ring inner diameter:18.4mm(0.72"),Ring circumference:2.24"-2.32") #9 (Ring inner diameter:19.3mm(0.76"),Ring circumference:2.36"-2.4") #10 (Ring inner diameter:20mm(0.78"),Ring circumference:2.44"-2.52") #11 (Ring inner diameter:20.7mm(0.82"),Ring circumference:2.48"-2.56") #12 (Ring inner diameter:22.6mm(0.89"),Ring circumference:2.52"-2.6") Note: - DO NOT suitable for bathing,diving,swimming,water-related work