Protect your home with the Yale AC-DC Alarm Door Contact. This sensor will trigger your Yale alarm whenever the door or window that it's attached to is opened. The contact is battery-powered & wire-free, so it's easy to install, & it works up to 200 m away from the control panel, so you can use it on sheds & outbuildings as well as in your home. The Yale AC-DC Alarm Door Contact pairs with the Yale Intruder & Yale Sync alarm systems.