The Edwards 871P DC Series are low-current, high decibel panel mount vibrating horns for heavy duty use. Supplied complete with gasket and UL listed to NEMA 4X enclosure requirements. Designed for semi-flush panel mounting, using supplied mounting template, or installation on a 4 in. square box. For NEMA 4X installation, mount to a NEMA 4X enclosure having a flat, smooth surface using supplied 1/8 in. gasket in accordance with the installation instructions provided with the unit.