A magnet contact is a part of an alarm system that is used for detecting the opening and closing of doors or windows. There are built-in and mounted magnet contacts. A built-in magnet contact is installed between the door or window and the frame of the window or door. A mounted magnet contact is installed on the outside of the frame of the window or door. When a door or window is opened a message will be send to the alarm system to notify of a security breach. It is important to choose a magnet contact that is reliable and easy to install.