Abstract: The invention is an improved burglar alarm for doors and windows or other similar openings in an enclosure to be protected against secretive entry. The invention consists of a series or plurality of bell-like devices which are automatically dumped or knocked to the floor when entry is made, thus creating an alarm noise. The alarm is operable on doors or windows that swing or slide, or which open inwardly or outwardly. The alarm is of simple construction and easy to install, consisting of a plurality of bell-like elements, a supporting rod, mounting apparatus for the supporting rod, and a wiper member for certain mounting positions.