Multiple Application Horn kit. Several mounting abilities and locations to fit most bikes, namely Yamaha V-Stars, Road Stars, and any other bikes with frame mounting ability or engine guards. These horns give a loud warning blast of 128 decibels all chrome finish. 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.