This is Ajax CCTV Alarm Systems DOORPROTECT (WHITE) Wireless opening detector that notifies of the first signs of room intrusion by means of a broken door or window. It can be mounted on all types of doors, including a metal base.
It can operate in the transmitter mode, sending a signal from the wired sensor to the hub. The device consists of two modules — a detector and a magnet.
Wireless Opening Detector
Ava Harvey –
This is a great buy