J2 Engineering For Corolla E170 3" Muffler Tip Exhaust Axle Back/Catback System Made of High Quality T-304 Stainless Steel with Computerized Mandrel-Bends for Strength and Durability i.e. Maximizing Smoothest High Exhaust Air Flow Rate TIG Welded CNC Machine Flange for Resistance against Pressure and Corrosion Aggressive Deep Sound while Ensures Smooth Exhaust Gas Flow Dyno Proven to Instantly Increases 20 -25 Horsepower/ Low End Torque Muffler Exhaust Tip Diameter: 3" (OD)/ Inlet: 2" (OD)