This CNC machined flange allows all of the Greddy blow off valves (Type-S, Type-R & Type-RS) to clamp right on to all 86-91 Mazda RX-7's Tricked out 2 piece designed has a 1" inlet to provide a perfect fit and Leak-Free seal. Made of billet aluminum. Slips into place using the stock hose & clamp. Lightweight & allows EZ replacement of the stock BOV.