These are the two additional idlers you need if you already have a 3 piece supercharger belt idler kit or double idler kit. Larger idler replaces the serpentine belt tensioner idler, located on the lower right front of engine . The smaller idler replaces the lower idler pulley for the serpentine belt. These idlers are known as the 4th and 5th idler kit. Both idlers replace the OEM molded plastic idlers that are known to fail on these engines, * Made from solid Billet aluminum in the USA. * Uses the famous NACHI bearings, known as the top performance bearing in the industry. If you have all OEM idlers, please see our complete 5 piece idlers set on this site,

Fits all 2003-2008 M113k engines with supercharger. E55, CLS55, SL55, CL55, S55, 

Fits 2005-2011- G55, 

Includes 2 x black idlers