Pontoon Boat Mini Compact Horn with Bracket Pontoon Boat Mini Compact Horn with Bracket is constructed of powder coated steel. Includes 304 stainless steel bracket for easy mounting. Recommended for fresh water applications. At 111 decibels and a frequency (Hz) of 370±20A, this horn meets US Coast Guards COLREGS and ABYC standard A-23 for use on vessels under 12m (39). 12VDC. NMMA Type Accepted #2601746.