[MULTI FUNCTIONAL] - Monitor heart rate, body temperature, sleep quality, and track steps for constant insights into your health.[CONVENIENT PHONE CONTROL] - Control your phone camera with a simple shake of your hand within arange of 5 to 8 meters.[IPX8 WATERPROOF] - Waterproof up to 100 meters, ideal for swimming, surfing, sailing, and deep-sea diving activities.[CHARGING CASE INCLUDED] - Never worry about running out of battery, simply place thein the charging case for convenient and easy charging.[STYLISH AND LIGHT] - Made with sturdy aluminum alloy and ceramic, this lightweight smartoffers both durability and an elegant look.Spec:Item Type: Smart Material: Aluminum alloy, ceramic, electronic components Battery Type: Lithium battery (built in) Battery Capacity: 20mAh Battery Life: About 7 days Charging Time: 45 minutesCharging Case Battery Type: Lithium battery (built in)Charging Case Battery Capacity: 350mAhColor: Silver NumberApplicable Finger Circumference US SizeInner Diameter 17 52.12mm/2.05in 5.5/6/6.5 17mm/0.67in 18 55.26mm/2.18in 7/7.5 18mm/0.71in 19 58.4mm/2.30in 8/8.5 19mm/0.75in 20 61.54mm/2.42in 9/9.5/10 20mm/0.79in 21 64.68mm/2.55in 11/11.5 21mm/0.83in 22 67.82mm/2.67in 12/12.5 22mm/0.87inPackage List:1 x Smart 1 x Charging Case1 x Charging Cable1 x InstructionsHow To Use:Before use, please scan the QR code to download the APP and follow the instructions. Power on method: Self start when fully charged.Note:When using, the sensor should be tightly pressed against the skin to achieve the best effect.