Mandrel Bent Tubing, Full 1 5/8" Primaries, 2 1/2" Collector, V-Band Collector, Collector Merge Spikes, Port Matched Flanges, 4.8L, 5.3L, 5.7L, 6.0L, 6.2L Engines CNC Machined Flanges, Polished 304 Stainless Steel