For Mazda 3 Mazdaspeed3 Dual 4.5" Muffler Tip Stainless Steel Catback+Downpipe Exhaust System - MPS Turbo Made of High Quality T-304 Stainless Steel Material TIG Welded CNC Machine Flange Increase Engine Output and Efficiency; Instantly Gains Up to 10 - 15 Hp./Tq. Catback - Muffler Tip Type: Dual Slanted Tip / Tip Diameter: 4.5" / Piping Diameter: 3" Downpipe - Inlet Size: Standard Mazdaspeed3 5-Bolt Flange / Outlet Size: 3" / O2 Sensor Bung and Flex Pipe Insertion