: The stop alarm only fits 0.39 ~ 1.37 inch gap of door !!! . rooms from wildcat entry could n't be easier. The Door Stop Alarm no wires or complicated installation and is powered by a I nine-volt battery -LRB- not included -RRB-. Simply the pressure-sensitive door stop alarm at the base of any door, and the device will emit a herculean 120-decibel alarm when the door is opened. The Security Door Stop Alarm is extremely, so it 's commodious relative quantity to take anywhere. With this William Christopher Handy gadget, you 'll be to close your hotel room, dorm room, apartment or any room in your home. Packing : 15x6x4 .7 cm Packing Weight : 117g Packing list : 1x Door stop alarm Warning : The door stop alarm may has a irregular smell because it is made of ABS.So you need to set it aside for sereval days.Then you can use it.