These MagnaFlow direct fit catalytic converters are designed for easy bolt-on installation for the professional installer. Welding, cutting, and tube-bending equipment are not required. They feature a ribbed body that minimizes expansion and distortion when the converters heat up. The ribs form a channel that protects the cushioning mat from direct exposure to exhaust gases, and they hold the ceramic catalyst in proper alignment. These converters use a monolithic honeycomb catalyst. The ceramic coating is designed for maximum flow and surface area, and the coating method is strictly controlled to maintain exact specifications. An improper coating could result in flow restrictions or an emissions test failure. These converters are designed to exact OE specifications and are available for the most popular vehicle makes and models. This is a stainless steel system in 2.5in in diameter that tapers at the end to mate into the factory exhaust system.