China (Mainland) Wireless Security System

Specifications: The small, simply security system include 4 parts, Wireless siren, Wireless PIR motion detector, Wireless door sensor and Wireless controller. All the 4 parts are wireless, removable, user only needs to screw the door sensor at the border of the door. All the 4 parts use battery power supply, you never seek a 110/220V outlet, you can put/hang them anywhere.