-Band Flange and clamp set fits the compressor outlet on the GT42, GT42R, GT42RS turbos. 3.5" v-band machined flange allows typical weld on application or use the extra length and lip built in as a 3.5" hose slip on (has the proper width for a T-bolt clamp also). Also has a nice inside smooth taper following the compressor discharge. Flange is O-ring grooved and o-ring provided to seal seamlessly against the face of the flange on the compressor housing.