Tial's new "Q" Blow off valve flows 60% more air than their previous 50mm design and flows more than any other BOV on the market. This American made high flow blow off valve features full cnc 6061 aluminum construction, anodized in several different color options. The valve seal utilizes a Viton O-ring that is clamped in place to prevent the possibility of sticking to the seat and pulling out. The valve stem and guide are Teflon-lubricated, hard anodize-coated for wear resistance. The V-Band design aluminum mounting clamp gives a very clean and unique appearance. The clamp is anodized and uses Stainless Steel hardware for a long lasting, corrosion-free appearance.Included is either a steel or aluminum weld flange, v band clamp assembly, banjo fitting and hose barb and instructions to make this ready to install. Please select from the options below when ordering- spring selection is based on your engine vacuum.