MaxBlast Air Horn - Mini Single Trumpet - Chrome MaxBlast Mini Single Trumpet Air Horn is constructed of durable chrome plated brass. When installed, the trumpet should point slightly downward to permit water drainage. Display pack includes horn, compressor, air tubing, and mounting hardware. At 124 decibels and a frequency (Hz) of 630±15A, this horn meets the US Coast Guard's COLREGS, US Inland Navigation Rules, Annex III Regulations, and ABYC standard A-23 for boats up to 20 meters (66’). 12VDC. Maximum: 20A. NMMA Type Accepted #2577056 & 2577057. WARNING: This product can expose you to chemicals which are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to P65Warnings.ca.gov.