Weld-On Flange Kit for Greddy Blow Off Valves is machined from high-quality 6061 aluminum for a durable and lightweight connection. This kit includes an O-ring to ensure a leak-free seal and comes with a radiused weld fitting, allowing the mating flange to be screwed on easily. This design offers a convenient option to switch to a different blow off valve in the future without replacing the weld bung. Each flange kit is sold individually.