Like a fire extinguisher in your house, or an earthquake kit, it's always better to be prepared. Although rare, Diesel Engine Runaway is caused when external hydrocarbons are drawn into the engine and can cause overspeeding and catastrophic engine failure. Life, limb and your vehicle are put in jeopardy. BD Diesel Performance has you covered should the worst happen with our Positive Air Shut-Off (PAS) by cutting the intake air supply to the cylinders and safely shutting down the engine. The Positive Air Shut-Off butterfly valve design simplifies the number of parts and reduces the overall size as compared to competitive units and uses aluminum and stainless components plus weatherproof electrical connectors to prevent corrosion. Easy installation with bead boot locks - no need for welding. Standard applications include over-speed electronics and CAC pipes included for some vehicles.Emergency Engine Shutdown; The most effective method to emergency shutdown engine is to cut the air supply; Butterfly valve placed in-line in the air intake system; Heavy duty electrical solenoid trips a locked safety cam causing the engine to shutdown within seconds; Unique locking lever holds valve; Unique bead lock keeps boots in place, no welding required!; Reduced overall size as compared to competitive units; Aluminum and stainless components plus weatherproof electrical connectors to prevent corrosion; CAC pipes included for some vehicles; Automatic engine overspeed electronics; Our goal is to be an innovative company and a world class manufacturer that distributes products Worldwide for North American Diesel vehicles.; Our goal is to be an innovative company and a world class manufacturer that distributes products Worldwide for North American Diesel vehicles.