The iON Plunger recessed sensor is a reed switch magnet contact transmitter that provides concealed protection for a door. The transmitter is powered by a long-life lithium battery that is easily replaceable when a low battery condition is indicated by the control. Each iON Plunger has its own unique identification code (serial number) permanently assigned during manufacturing. The control unit is required to enroll the transmitter s ID during installation of the alarm system. FEATURES: Fully concealed. For residential and commercial applications. Aesthetic: Fully concealed wireless door sensor. Simple to specify: Compatible with current DSC GE HAI and 2GIG Wireless receivers. Easy to install: Only a drill a 3/4-inch Forstner bit and a 1/4-inch wood bit (for antenna insertion) are required. Composition: Micro-processor Micro-transmitter Lithium Battery Optimized Antenna for superior zone signal. Long-life Battery: 5+ years (average rating). TYPE: Compatible with current 2GIG Wireless receivers.