You can use the Super Door Stop Alarm as an entry alarm and to block the door from being opened. If anyone tries to open the door a 120 dB alarm will sound. The super door stop alarm stops when pressure is released from the doorstop plate. The super doorstop alarm also has a movement Sensor with adjustable sensitivity so that the alarm will activate if the alarm is tampered with. The super doorstop alarm has an off/on switch on the back of the alarm and includes a low battery indicator. The door stop alarm uses one 9 V battery (not included).