Wireless door/window sensors are used to detect when a door or window is opened. These are called Reed switches. They consist of the Reed switch sensor and a small magnet. The Reed switch is placed on either the frame of the door/window and the magnet on the opening part of the door/window. When they are separated the sensor sends a signal to the alarm control panel. If the alarm system is armed it will be triggered.
Door/window sensors are a good idea if you want to have perimeter protection for your premises. This also means you can set your alarm at night and still move freely about your home without setting the alarm off. This is called night/home/stay mode.
Specifications:
Transmission range: 40 metres (open area)
Transmission range: 30 metres (through two walls)
Battery Type: 1 x AA Alkaline
Battery life: 1 year
Battery Type: 1 x AA Lithium
Battery life: 4 – 5 years