Sea-Dog Hidden Horn V.1 w/Grills Drop-In. 1 with GrillsDrop-In Hidden Horn V.1 with Grills is constructed of powder coated steel and injection molded nylon. Kit includes horn plus one chrome and one white decorative billet snap-in grill. Hole size 1-7/8" x 3-3/8". At 106 decibels and a frequency (Hz) of 44020A this horn meets US Coast Guard's COLREGS and ABYC standard A-23 for use on vessels under 12m (39'). 12VDC. NMMA Type Accepted #2577064. Specifications for Sea-Dog Drop-In Hidden Horn V.1 w/Grills: Manufacturer: Sea-Dog Color: Black Features of Sea-Dog Drop-In Hidden Horn V.1 w/Grills 106 decibel volume / Frequency (Hz) 44020A Meets ABYC standard A-23 For use on vessels under 39' Kit includes horn plus one each chrome and white decorative billet snap-in grills Required hole size 1-7/8" x 3-3/8" Package Contents: Sea-Dog Drop-In Hidden Horn V.1 w/Grills Sea-Dog 431210-1: Hidden Horn V.1 w/Grills Drop-In