This is a direct bolt - on replacement for the factory bypass valve and was designed to the be THE BEST blow off valve on the market. Using a large 44mm piston and Viton O - rings to withstand the high air charge pressures and outlet temperatures from your turbocharger. Made in the USA, every detail on this valve screams quality and precision, right down to the position of the Hybrid Slot and shape of the Vent to Atmosphere Port making that perfect Psssh between shifts.