1/5/10PC Wireless Security Burglar Alarm Home Window Door System Magnetic Sensor
(4) Open the door and see if the siren sounds. 1or 5or 10Pcs x Set of Alarm Unit(1 Alarm + 1 Sensor). Sensor Type: Sound Alarm. Alarm Unit: 4.5X1.5X1.5CM. (1) Fix the host to the door / window with double-sided tape.