Low current, high performance, high decibel signaling appliance designed to function as either a horn or siren by setting an internal, tamper proof switch. The 5520D is primarily intended for use in applications requiring electrical supervision of signaling circuit field wiring. These signals may also be used for unsupervised signaling applications.

The signal's universal Adaptaplate ^® mounts directly on walls, or on any single-gang opening. Adaptaplate speeds installation by allowing the installer to connect all field wiring to the plate and then finishing the installation by snapping the horn onto the plate. It also mounts to 3 1/4" (83mm), 3 1/2" (89mm), 4" (102mm) octagon, 4" (102mm) square boxes, or equivalent fittings. The signal may be weatherproofed using the Edwards Cat. No. 349 back box.

Used for schools, factories, lumber yards, and commercial installations. The horn signal is often used for timing, paging, and burglar and fire alarms. The siren signal is particularly suitable for alarm and evacuation in high noise areas.