Specifications material tpu strap anodised aluminium main body and buckle display oled battery type rechargeable li poly battery with usb charger battery life up to 5 days depending on usage and settings water resistant 30m100 feet 3 atm sensors amp components optical heart rate tracker 3 axis accelerometer vibration motor connectivity bluetooth low energy 40 ant memory saves 7 days of activity data stores heart rate data at 1 secon