These compact horns feature ASA plastic covers for impact and UV resistance. Integral mounting bracket can be used as a wiring template. Horn wiring has no polarity, so the negative or positive wire can be attached to either side. When installed, horns should point slightly downward to permit water drainage. Decibel rating at 1 meter: 108 dB. Meets ABYC standard A-23, NMMA type accepted #748110, for use on vessels under 39'. 12VDC.