Increase your 2009-2013 ZR1 Corvette's performance with a 2.60" supercharger pulley specifically designed for the LS9 engine. The 2.60" pulley is designed to increase your supercharger's drive by 19% while increasing RPM to 18,300 - without changing the harmonic balancer.The 10-bolt attachment is designed to be used with Lingenfelter's hub assembly for quick and easy pulley changes. Hub assembly (Zip # PM-659) must be purchased separately. Use in combination with a 100mm idler pulley and the stock serpentine belt.