ELK 6021 Two-Way Wireless Mini Window Sensor, White

Exceptionally thin wireless window sensor designed for double hung and casement style wood and vinyl windows. Features industry-leading two-way technology for reliable communication with compatible wireless transceivers. What's Included Mini Window Sensor 3V Lithium Battery Key Features One built-in reed switch for window open/close detection Compatible with two-way wireless transceivers 902 MHz – 928 MHz frequency hopping technology Available in white and brown finishes Perfect for home security and automation systems, this slim profile sensor installs discreetly without interfering with window operation.