Help secure any door or window in your house with the Sabre Door or Window Alarm. This compact, magnetically-triggered alarm blares out 120 decibels when a window or door is opened, deterring any intruders from entering your home. A chime setting can also be activated to alert you when children or welcome visitors are coming and going. Easy-to-install, self-adhesive pads are included, allowing you to set up your sensor in seconds. Easy to change between off/chime/alarm settings. Low battery test button. Batteries (included): 4 x LR44 per alarm.