Super Door Stop Alarm Simply place the alarm behind any door. If an intruder attempts to open the door, the wedge-shaped design will prevent it from opening and activate a 100 dB alarm. The alarm will scare off the would-be intruder and alert you to the attempted entry. The on/off switch allows you to silence the alarm as needed. When traveling, just toss this lightweight unit in your luggage. Requires two AA batteries that are not included. Measurements are approx. 6" x 2" x 2". more »