alarm when they push the door or window Mode of installation: magnetic control ? alarm sound of 90 decibels The use of 3 Pieces 1.5V batteriesԺànot containԺâScope: 1. doors, windows, families, shops, merchants and other wide places, 2. Internet cafe computer case burglar burglar device installation is convenient, only the main and auxiliary parts are attached to the box cover and the chassis, or two windows, and align (5 millimeter left or so clearance). When someone illegally hits the box or window, the alarm can be sent out to warn the intruder to leave. When you want to open the chassis, doors and windows, you can control them by switches. It is suitable for anti-theft in Internet cafes, residential buildings, offices, shops and counters. Product Description: Simple and practical and effective (alarm bell double) a sticker on the door, a post on the box, in the alarm state: if someone opens the door, if someone opens the door, 100dB alarm sound will be sounded, you sleep the fragrance will be awakened, thieves can not quickly slip. Two, in doorbell state: during the day, doorbell can also be used. If someone opens the door, it will ring two times when the door is opened. If the door is opened again, it will ring two times, and it will be used for burglar alarm or doorbell.