Hipipooo I5 Plus Smart Wristband Bracelet Bluetooth 4.0 with Sleep Tracker Health Fitness For Android IOS(Black) [Prime] DFWL US is an authorized seller of PEIBO products, products purchased from a non-authorized seller/distributor may be fake and will not be covered by our warranty. Also, we use Fulfillment by Amazon (FBA) service. Amazon picks, packs, and ships our orders, which ensures fast shipping. Multifunction Health Manager: 24-hour heart rate monitoring and activity tracking, auto sleep tracking to help you know your everyday health status Bluetooth version: 4.0BLE Charging & Battery Capacity: Easy charging via USB cable on computer, laptop, notebook, power band, or directly charging with AC 5V/500mA. High quality rechargeable polymer Li battery(70 mAh), provide long duration(5-8 days for standby time, 2-3 days under operation).