Prewired, sealed sound unit with 304 stainless steel diaphragm and stamped 304 stainless cover. Integral mounting bracket can be used as a wiring template. A drop-in replacement for many common OEM horns. When installed, horns should point slightly downward to permit water drainage. Meets ABYC standard A-23, NMMA type accepted #748110, for use on vessels under 39'. 12V DC.