This Wireless Mini Door / Window Transmitter is used for protection of doors and windows in installations where the transmitter and magnet can be visible but inconspicuous. The supervised transmitter and contact comes with a case tamper switch, wall tamper switch, and a replaceable Lithium battery. The Wireless Mini Door / Window Transmitter is a single zone, miniature version of the existing Three Zone Door / Window transmitter with mercury tilt switch for garage doors. Works with the HAI Wireless Receiver.