KERUI 433MHz Wireless Door/Window Magnetic Sensor For GSM Home Security Alarm Systems

Designed to detect if a door/window or anything it is affixed to is open or closed. When the transmitter is separated from the magnet more than 1cm, the sensor will instantly send an alert signal to the host it is paired with to alarm. Compatible with ALL KERUI ALARM SYSTEM. The D022 door/window contact runs on 433MHz radio frequency, and it needs a home and business security system base unit to be paired with in order to operate, cannot work alone. Communication distance from the base unit is up to 250 feet away unobstructed. The antenna can be drawn out to maximize its transmission range. Battery operated with one (1) 23A 12V battery (Included), easy to mount with double-sided tape (Included). Low Battery Indication. When the battery run low, LED 2 will turn on red and stay on, to notify you that the battery needs changing otherwise it could not function properly., Manufacturer: KERUI