Can be easily installed in 20-30 minutes. The trumpets are triple plated chrome as are the mounts and brackets so the shine and finish will last for years to come. No hole drilling is required with bolt-on, plug-in installation. Cone shaped covers are included which mount to the front of the trumpets.All kits include two horns, air compressor, relay, simple wiring and complete installation instructions. The horns replace the stock horn and the compressor is either mounted under the seat, behind right side cover or on down tube of frame, (Different models vary) The air compressor creates instant air pressure to the horns. Since the pressure is created so fast there is no need for a storage tank as on Semi Trucks and RVs. Although the pressure is very low (12-15 psi) it delivers a large volume of air (3 CFM or cubic feet per minute). This low-pressure high volume air supply causes the diaphragm inside the horn to vibrate at a high rate of speed or frequency, the exact speed at which it vibrates is varied by the length of the horn or trumpet. Together the horn set produces an extremely loud 128-decibel warning blast. This is approximately 4 times louder than most electric motorcycle horns, which usually rate at 87 decibels. The item "Rivco Air Horn System Black Horns Harley Davidson Touring Softail XL Dyna Custom" is in sale since Tuesday, December 23, 2014. This item is in the category "eBay Motors\Parts & Accessories\Motorcycle Parts\Electrical & Ignition\Other Electrical & Ignition". The seller is "americanclassicmotors" and is located in Zieglerville, Pennsylvania. This item can be shipped worldwide.