Features: 1) Connection mode: Bluetooth 4.0 2) Battery capacity: 157mAH 3) Standby time: 5 days 4) Suitable for young and middle aged white collar workers and old people 5) Bracelet length: 247mm 6)Adjustable length: 145mm to 209mm 7)Waterproof gra de: IP54 (Don't take a shower or wash clean with suggestions) Package Content:(1) Normal One1 x 37 degree bracelet1 x wrist strap1 x manual1xBuckle