Wolo (160) Ocean Alert Chrome Plated Dual Trumpet Horns - 12 Volt, Low and High Tone 12 volt, low and high tone Dual trumpet air horn constructed of solid brass that has a bright chrome plated finish and the horns base plate is made of stainless steel Designed smaller in size making it ideal for smaller boats, producing a powerful warning sound equal to larger horns Lexan non-corrosive diaphragms to provide years of dependable service and making Ocean Alert ideal for boats in salt or fresh water environments The 12-volt compressor included, is heavy-duty, compact in size for easy installation and is maintenance free