The door/window detector has a built in magnetic contact that activates the security system when the window or the door were the detector mounted is open.This detector allows you to proctet all the entrances in the building. The detector is powered by two AAA batteries and is connected with the security system via a wireless comunication, this means that the installation of the detector is simple and requires a minimum effort. The security system checks if the detector is ok. If there is a fault (low battries, problems, etc.), she is reported to the security system.