Interlogix DesignLine Crystal Wireless Slim Door/Window Detector Low-profile design -- Gives sleek, modern look; fits in any home or business Wireless technology -- Easier and less costly to install; safer because of flexible placement Advanced circuit technology -- Supplies robust function with low current draw Compatible with all GE Security 319.5 MHz control panels and receivers Range -- Functions at open-air distances of up to 500 feet Battery operated -- Runs on lithium coin cell battery with typical life of 5 years Tamper-resistant case -- Inhibits tampering and improves security and durability External contact header allows connection of an external hardwire contact