The PW39 is made from high grade, high temperature stainless steel and billet aluminum components. It features Precision's own purpose designed Kevlar reinforced wastegate diaphragm and a 347 stainless investment cast valve body. Precision's investment cast valve body has a smooth internal surface, giving you better flow and more accurate boost control. Precision's PW39 was designed to be a direct replacement for other existing 44mm wastegate flanges, but will work best with the flange provided. The PW39 features a Nickel Chromium Alloy valve and 5 different 17-7 precipitation hardened springs. Also included are stainless steel inlet and outlet flanges with clamps. With a satin black anodized, 6061 aluminum billet wastegate cap you will have years of good looks and protection from the elements. The PW39 is generally compatible with most aftermarket manual and electronic boost controllers on the market today.