feature: It has a built-in PIR motion sensor that activates an alarm if any motion is detected. Installation is simple, no wires to connect, just put in the required batteries (4 AA's required, not supplied). Alternatively, you can use a 6v adapter, or you can use one not included with the unit, to secure to a suitable surface and turn it on with one of the included remotes. Ideal for protecting your property from unwanted intruders. It can cover front doors, back doors, garages, sheds, outbuildings, and more. It is also suitable for large cars and RVs. Specification: Powered by: 4 AA batteries (not included) Loud: 105 decibel alarm material: plastic Size: 12*88*50mm Type: Wireless Magnetic Alarm white color Package Included: 1 x alarm sensor 2 remote controls 1 x Mounting Bracket