It also offers you safety when traveling. Requires one 9 volt battery and 2 C batteries - not included. This one of a kind device is recommended for all bathroom and bedroom doors that have locks at the handles. Doors can be forced open when time is of the essence. Special design of the Door Lock Release will cause tumbler to retract when force is applied to the door, without damage to the door.
Unit replaces regular strike plate.
Don't be fooled by other companies fine print.