Viking Horns V202 Loud 149dB Semi Truck Single Metal Chrome Trumpet Air Horn Electric Valve Sound output: 149 Decibels at 150 psi Construction: All metal, chrome plated trumpet with weather protection cover Power Suorce: 12 volts. Reqiures an on-board air system Mounting Hardware: Bolts, nuts, washers, mounting gaskets Horn Dimenstions: 25-1/2" L, 5-1/2" H, 7-3/4" W