For Honda CRZ Catback Exhaust System 4" Tip Muffler - ZF1 Made of high quality T-304 stainless steel. TIG welded CNC machine flange for resistance against pressure and corrosion. Aggressive deep and smooth tone sound while ensures smooth exhaust gas flow. Increase engine output and efficiency. Muffler Tip Type: Dual Rounded Tip / Tip Diameter: 4" / Inlet / Outlet Size: 3" / Removable Silencer Included / O2 Sensor Bung Insertion