For Corolla 4" Muffler Tip Catback Exhaust System - E100 AE101 AE102 Made of High Quality T-304 Stainless Steel with Computerized Mandrel-Bends for Strength and Durability Dyno Proven to Instantly Increases 10-20 Horsepower/ Low End Torque TIG Welded CNC Machine Flange for Resistance against Pressure and Corrosion Aggressive Deep Sound while Ensures Smooth Exhaust Gas Flow; Increase Engine Output and Efficiency 4"(OD) Muffler Exhaust Tip with Removable Silencer; Inlet: 2.5"; Main Piping Diameter: 2.5"; O2 Sensor Bung Insertion Included