2 pack, wireless, window & door alarm, alarm sounds when window or door is opened, 2 sound setting:120 db siren or chime by using the off/chime/alarm switch, can be attached to windows, doors, sheds, cabinets, gates & more, features low battery test button, sensors can be attached to windows, doors, sheds, cabinets, gates & more, each alarm uses 4 lr44 batteries, included.