Wireless Home Security Alarm System, Autonomous Magnetic Sensors, Anti-Burglary, for Doors and Windows Features: 1. Alarm function: when someone artificially opens the door or window (the main and auxiliary parts are separated by more than 10mm), the alarm can emit 90db alarm sound to warn the intruder to leave. When you want to open the door or window, you can control it by the switch. Use a button battery (included in the machine). 2. Easy to install: This product is easy to install, just stick the main unit on the door frame, and stick the auxiliary machine on the door or two windows, the arrows of the auxiliary machine are aligned with the side markings from the main machine. 3. Uses: It can be installed on doors and windows with a switch. When the switch is open, if the doors and windows are opened, the alarm will sound. When you go to bed at night or when you are not at home or in the office, you can turn on the alarm switch to prevent theft. Description: The alarm uses magnetic induction control technology, with long service life and simple and convenient installation. Adopt self-adhesive paste, no screw installation, directly paste, you can use! Specifications: Color: white Size of the single product: 6.2cm long Raw material: ABS + electronic components Package Included: 1 set of home security alarm