The Edwards 873 DC Series are low-current, high decibel single projector vibrating horn for heavy duty use. The single projector is designed to channel sound in one direction without decibel loss. Supplied complete with Adaptaplate for easy installation. Supplied Adaptaplate allows quick plug-in connection. Horn simply plugs into receptacle on mounting plate. See Adaptahorn installation and Accessories page. Also mounts on any single gang, 3-1/4 in., 3-1/2 in., 4 in. octagon or 4 in. square box. Used in industrial, commercial, and institutional applications for timing, paging, and alarm signaling. Typical applications include signaling equipment malfunction, security, and employee communication.