the gfb mach1 is a good sounding fairly cheap bov. the kit contains the adaptor and 25mm plug and can be fitted with the standard pipework from our cars, even using the standard clamps. fittment takes just minutes and can be either ,fullsick, vent to atmo with a trumpet or plumback by unscrewing the trumpet and screwing in the supplied pipe to go to the standard plumback system. price should be around $250