Door Window Alarm Home Security Wireless Magnetic Sensor Burglar AntiTheft Alarm Pack of 8

Operating Instructions: Convenience in installation--just peel and stick  The sticker is supplied free in package  Operated by 3pcs of 1. 5V LR44 / AG 13 button cell ( included )  1. Use the double-side adhesive tape to fix the main unit at the side of the door/window. Attach the bar magnet to door frame/window frame with the arrow aligning with the refernce line of the main unit. 2. Test the setup by switching the system's switch to "ON" position of the main unit and see whether the alarm can be triggered by opening the door/window. Specifications  Sensor type: Window Door Alarm  Alarm type: Sound  Material: Plastic  Color: White Size: 2.5 x 1.3 x 0.8 inch  Package Included:  8 x Magnetic Sensor  8 x Magnetic Stick  24 x LR44 Button Battery