Pontoon Mini Compact Horn with Bracket by Sea Dog®. At 111 decibels and a frequency (Hz) of 370±20A, the Pontoon Boat Mini Compact Horn meets US Coast Guard's COLREGS and ABYC standard A-23 for use on vessels under 12m (39'). Constructed of powder coated steel with corrosion resistant 304 stainless steel bracket for easy mounting. Recommended for freshwater use. NMMA Type Accepted #2601746. 12VDC.