Depending on your engine and type of vehicle, the exhaust can either be a set of pipes or it can be a cast iron assembly. Essentially the exhaust takes the burned exhaust gases from the engine's cylinders and ejects the gas through the exhaust system and out through the car's tail pipe. The exhaust gasket seals the surface of the exhaust to the surface of the cylinder head, preventing leaks in the system. Over time, the constant expansion and contraction of the components (caused by constant heating and cooling in the engine), may cause the gasket to leak. These leaks can be hazardous as hot exhaust gases escape and can damage other components in the engine compartment. A leaky exhaust gasket can also impact engine performance. So replace your gasket and regain back lost performance. Replace for 06-09 C230, C280, CLK350; 10-11 C250, ML450; 08-11 C300; 06-11 C350, E350, R350; 2012 C300; 07-09 E280; 09-12 GLK350; 05-11 ML350; 10-13 S400; 06-08 SLK280; 09-11 SLK300; 05-08 SLK350