Pacesetter 324202 Rear Catalytic Converter for Nissan Altima 2.5L Engine Lower cost direct fit alternative for OEM. 49-state smog legal applications Stainless steel construction. 3/8inch thick CNC-machined flanges insure a perfect fit Mounts for heat shields (where applicable). Manufactured using mandrel-bent 16-gauge 2 1/4Inch diameter stainless steel tubing More efficient, low restriction tubular design Manufactured with EPA approved catalytic converters