Acepro 12v Air Horns Dual Trumpet Super Loud with Compressor Twin Tone Material : Chrome Plated ZINC Trumpets(Non-Rusting) Overall Works on any 12 Volt Vehicle including Cars, Trucks, Vans, Motorcycles, Buses, and Boats Twin Horns with High/Low Tones Combine for one HUGE Sound Super-Loud 135 dB sound can not be ignored WARNING: This horn can be mistaken for a real train horn. Do not use it near train tracks.