The 870EX series vibrating horns are heavy duty, explosionproof, high-decibel horns designed for use in hazardous locations. Diode polarized versions are also available. They are intended for use in hazardous locations requiring electrical supervision of signaling circuit field wiring. May also be used for unsupervised signaling applications. Two mounting brackets are provided on either side of the unit for wall mounting. The housing is tapped on one side for 3/4 in conduit to allow for field wiring installation.