ISR Aluminum Modular BOV Flange (Greddy Style BOV's)
ISR Modular Aluminum Greddy Style Blow Off Valve Flange.
This flange is designed in 2 pieces. The bottom portion can be unscrewed, and welded to the pipe. Then the top piece can be threaded on. This makes for ease of welding and also give you the ability to switch between HKS or Greddy Style BOV's without rewelding.