• Each alarm installs in seconds with peel off double sided tape
• Alarms measure 2 1/2" long x 1" wide x 1" deep for easy concealment
• Runs on 1.5 Volt LR44 Button Cell Battery which are included in all 4 alarms
• Option 90 dB alarm, Chime & off - Chime is great for pool area with kids or alzheimer's
• Very inexpensive way of letting you know when doors are being opened

At only 2 1/2 inches long this economical alarm inconspicuously protects your home from intruders. This unit uses a magnetic sensor to detect the opening of a protected door or window. A 90dB alarm or a chime will then alert you to an attempted entry and scare off potential intruders. The owner may open the window or other protected object, without setting off the alarm by switching the on/off switch to the off position. May also be used within the home to alert parents to children opening a gun or medicine cabinet or used to protect exterior doors, particularly those hard to protect sliding glass doors. Commercial uses include showcases and cash registers. Batteries included.  Please note that this item must be ordered in multiples of 4 units.