Capacity mah75 materialabs tpu silicone connectionbluetooth30 bluetooth40 typesmart bracelet featuresfind my device sleep tracker creative water resistant water proof wearable sports health care multifunction distance tracking long standby pedometers alarm clock modeld21 sensorgravity sensor finger sensor heart rate sensor accelerometer proximity sensor supported operation systemiphone android ios screen typedisplay technologyoled stand by timeh120 150