UPD: Complete 3 piece idler, extreme duty, billet, supercharger 8 rib tensioner idler, smooth idler and 6 rib idler for 2009-2015 CTSV Cadillac / 2012-2015 ZL1 Camaro. Replaces all factory OEM heavy steel or plastic supercharger and accessory idler pulleys with high performance billet aluminum idler pulleys. Dual bearings are added to the high load SC idlers. These 3 idlers are designed to replace the other 3 OEM idlers not included with the 105mm and 50mm relocation. Includes: 1) 8 rib double nachi bearing supercharger tensioner bearing and bearing shield. (double bearing) 1) Smooth accessory tensioner idler with bearing shield 1) 6 Ribbed accessory idler and bearing shield This kit can be used on stock cars to help with supercharger belt wrap, reduce weight, increase idler durability and plan for future mods.