Fortress Security Store (TM) Contact Sensor for S02 or GSM System - Window & Door Sensors
The most likely method of forced entry into a home or office is via a door or windows. That's why it's so important to have contact sensors attached to the windows and doors on your home - at least on the ground floor.These magnetic sensors can detect any time a window or door is opened. If the alarm is armed, it'll be triggered - setting off the siren and, in the case of the S02/GSM system will call a sequence of designated numbers until someone picks up.Each pair of sensors requires one 'N' battery.