Shuts off the flow of fuel to the carburetor automaticallywhenever the engine shuts off insuring a minimum of fuel spillage out of the float bowl vent in the event of dropping the motorcycle on its side helping to keep fuel off a hot motor preventing a possible fire. This is a perfect fit for the Enduro racer that needs every drop of fuel available. Installs easily into the existing fuel line and includes an auxiliary vacuum hose barb to install wherever there is a vacuum source on the engine. CNC machined billet aluminum and comes in a matte gray finish with 5/16" hose barbs.