Max Blast Twin Mini Compact Horn MaxBlast Twin Mini Compact Horn is constructed of injection molded housing under the stamped 304 stainless steel cover, which protects the the internal components from corrosion. After a 600 hour salt spray test, this electric horn was completely rust-free! Mounting bracket can be used as a wiring template. When installed, horns should point slightly downward to permit water drainage. At 111 decibels and a frequency (Hz) of 490±20A, this horn meets US Coast Guard's COLREGS and ABYC standard A-23 for use on vessels under 12m (39'). 12VDC. Five-year rust-free warranty. 12VDC. NMMA Type Accepted #2577062. 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.