Vibrant performance makes it easy to weld Blow Off Valve mating flanges to your induction plumbing. Each blow off valve flange kit includes a radiused weld-on fitting so that it can be easily welded to your induction tubing. The weld-on fittings is also threaded so you can simply screw on the mating flange. The weld fittings are available in either T6061 Aluminum or Mild Steel construction. The flanges are constructed of T6061 Aluminum and include an O-Ring for a leak free seal.