It has been almost 30 years since BD Diesel started shipping their first exhaust brakes. With that many hill and mountain roads experienced, we used the knowledge gained to continue to deliver the best designed exhaust brake for your application. Incorporating BD's exclusive Variable Orifice Technology, BD's solid, offset butterfly, spring loaded cylinder and pressure regulation provides up to 150 retarding horsepower throughout the engine's RPM range - not just at high rpm like some designs that use holes or additional parts and claim it as a better idea. A range of rugged, cast-iron housings for Dodge, Ford, Chevy and motor home applications that incorporate BD's exclusive alumibronze bushing, piston ring-seals and stainless steel butterfly shaft has proven to stand-up under the harsh, high heat conditions of the exhaust environment. BD's butterfly valve and rotating shaft are made of stainless steel to resist corrosion. An air compressor is included in most kits for newer pick-up trucks.