?Replacement Straps, There are two types of bracelets and replacement strap, You can change the color of the strap to match changeable weather, different feeling and various clothes. ?Easy to charge, fitness tracker comes with a built-in usb charger. Take the device off the straps, Use the side with metal chip to plug in a usb interface, check if the red light is on. ?Heart rate monitor and sleep monitor, it will record your daily heart rate and monitor sleep quality, Track your all-day activities like steps, distance, calories counter,and you can see these data in the app. ?Multi-sports Tracker. It provides 14 sports modes, 3 exercise modes on the screen, And with 14 sports modes to choose on the APP. You can try different sports to help your body building. ?Other Features, It will vibrate to alert you if your phone receives call, messages, And wake you up peacefully with a silent alarm. Fitness tracker suits for wrist size around 4.8 inch - 7.9 inch (13cm -20cm).