DO NOT BE FOOLED by replica knockoff bearings on Ebay. this is a GENUINE Nachi OEM Replacement Supercharger Bearing for ALL M113K Supercharged AMG Engines 2003-2006 E55, CLS55, CL55, SL55, S55, G55. This is a direct replacement of the supercharger pulley bearing for an OEM S/C Pulley.