For Honda B-/D-Series Engine Stainless Steel Turbo Downpipe/Dump Pipe - T3 Made of high quality T-304 stainless steel with computerized mandrel-bends TIG welded CNC machine flange for strength and durability Increase engine output and efficiency. Gain 10 - 15 HPs (approximately) O2 sensor bungs insertion, bolt(s) and metal gasket(s) included Fits T3, 5-Bolt Flange / Inlet/ Outlet: 2.5" / 2.375"