Hidden Mount Mini Compact HornHidden Mount Mini Compact Horn is constructed of powder coated steel. At 107 decibels and a frequency (Hz) of 440±20A, this horn meets US Coast Guard's COLREGS and ABYC standard A-23 for use on vessels under 12m (39'). 12VDC. NMMA Type Accepted #2577068. 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.