Direct fit for 2007-2012 Nissan Altima catalytic converters, it's for a whole set including front & rear parts. Please make sure your vehicle is fitted before purchase. certifications:OBD-II , Federal EPA , Non-CARB, material:Stainless steel, restricted states:California, New York, Colorado , Maine, fitment type:Direct replacement, substrate:Ceramic, placement on vehicle:Rear, interchange part number:54782, 324424, 643090, other part number:40919, 0961460, 58363, warranty:5 years or 50,000 miles limited