This multifunction alarm helps alert any unauthorized exits or entries through emergency exit doors. When the protected door is opened, the electronic Exit Stopper flashes and emits an ear piercing alarm (duration selected by the user). A key operated override will silence the alarm and allow authorized exits. Horn volume at 1 ft. is 95 dB low / 105 dB high. This indoor only product is ideal for almost any type of door, mounting or installation, including remote alarm placement. CE Approved.