Wolo's Persuader electric horns are 100% stainless steel 304 non-magnetic grade with a bright polished finish that will not rust.  Designed for exterior use and ideal for trucks, RV's and boats in a salt water environment.  Ideal for any 12-volt vehicle in almost any weather condition.  The Persuader maintenance free and does not require a compressor or hoses, saving time and money.  Includes a stainless steel adjustable trumpet support to prevent vibration.  Comes complete with rubber gasket and stainless steel mounting hardware.