Made from lightweight 6061 and 7075 billet aluminum, PTE's 33mm 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 PB33 also has a CFD designed valve and valve body for the highest flow even at low lift, while the attached O-ring seal prevents leakage. Furthermore, PTE's PB33 BOV also utilizes an innovative and industry-first proprietary wave spring for added weight savings while still holding the valve closed under high vacuum idling. Designed to release back up pressure created when the throttle is closed via a spring-loaded valve diaphragm assembly, PTE's PB33 BOV is a key component for preventing potentially harmful compressor surge back into the turbocharger to reduce wear on both the turbo and engine. Packaged with a weld-on aluminum mounting flange, spring adjustment screw, and two top ports for the ultimate in versatility and adjustability, the high-performance PB33 is generally compatible with most aftermarket manual and electronic boost controllers on the market today. Each unit is warranted to be free from manufacturer's defect for a period of 12 months or 12,000 miles.