This alarm works on a door or window and detects unwanted intruders. When activated, the alarm sounds a piercing siren when the magnetic contact is broken. Includes a programmable keypad for your personal security code, mounting hardware, double-sided adhesive tape for the magnetic sensor and instructions. Uses 3 AA batteries (not included). 5"L x 3"W x 1"D.
i am using these alarms for the doors for my special needs daughter that can open and run out and then get lost. so to prevent that this alarm is very loud and to the point.. so glad for the price of them.. now getting for a friend that needs for her niece.. thank you!