●Merge collector is made from T304 stainless steel schedule pipes for superior strengh and durability. ●Merge Collector: 4-1 ( 4in-1out) ●Pipe OD: 48mm (1 7/8"); Pipe Wall Thickness: 3mm; Height: 120mm (4 3/4") ●Inlet Flange Style: 3" V band flange (76.2mm ID) ●Professional Installation Only