Wireless Alarm & Door Chime Hampton Direct 20975 White NEW in package - for doors or windows. 

It comes with three 1.5v LR44 cell batteries which may need to be replaced due to age of product. 

The Wireless Alarm & Door chime can be used not only as a door and window entry alarm, but also as a door chime. To use as a visitor chime, move the switch to the "chime" position. When your guess attempts to enter your home by opening the door, a pleasant "Ding-Dong" chime will announce their arrival. The "Chime" setting can also be used to warn you if young children have opened the door to a medicine cabinet or basement, etc. When the switch is in the "Alarm" position, if a door or window are opened, the alarm will sound. The alarm will stop once the door or window are closed, or the switch is turned to the OFF position.