PTE PB64 64mm Blow Off-Valve (BOV)Made from lightweight 6071 and 7075 billet aluminum, PTE's 64mm unit is satin black anodized to be aesthetically pleasing yet functional while offering long lasting protection from the elements. It features a Kevlar reinforced silicon rolling diaphragm for quick response and a hard coat anodized valve stem for enhanced durability. The PB64 also has a CFD designed valve and valve body for the highest flow even at low lift, while the attached O ring