1 flange and 1 clamp to mate to "GT style 3" v-band discharge on "GT" style turbine housing. Heavy Duty Stainless Steel V-Band Clamp and special Stainless 3" flange with protruded lip for GT V-band housings with lip on V-band. Also same (slightly smaller) outer diameter as GT V-band housing outer diameter. Only use this flange if you have a mating flange or housing that has a recessed ID for the protrusion on this flange to sit into. If your mating v-band flange does not have a recessed ID, please use a 3" v-band flange via P/N: ATP-FLS-012 or ATP-FLS-063.