Sounds alarm when door or window opens, helps deter intruder and alert residenceIncludes five 120-decibel window/door alarm with three adjustable settings off/chime/alarmEasy and convenient to install, requires no wiring. All mounting hardware included, for indoor use onlyLow battery test button to easily check battery life, includes 1 Lr44 battery for each alarmPerfect for home, garage, apartment, dorm room, mobile home, RV, office and more