Kit makes a magnetic switch activated alarm to warn of a break in by an intruder Set it up in a doorway or on a window. When someone opens the doorway or  window the magnetic switch will activate and sound a high pitched arlam. Many uses in stores, garages or workshops. It could even be mounted remotely, garage or driveway etc, and have the alarm in the house so you will know when someone breaks in. Kit includes magnetic switch and delay / on off switch. Powerfull 2 watt amplifier with buzzer.