Viking Horns metal 4 trumpets Air Horn. Will produce a Loud Powerful Sound at 149 decibels. All the trumpets are chrome plated metal. Great for Car, Truck, SUV, RV, Boat, Pick-Up. Comes with a 12 volt electric valve (solenoid), mounting hardware, 8 ft. 1/4" OD high pressure hose, and installation instructions. Requires An On-Board Air System.