Wristband Personal Body Guard Alarm 1) Dimension: 43x59x18mm; material: ABS 2) CR2032 battery(included); 3) Press the button on the top to activate alarm, press the button on the back to stop alarm; 4) 120 Decibel 5) Especially be attached to the wrist; 6) Suitable for joggers, elderly, disabled, night shift workers, alone people.