6-bolt pulley hub spacer .140" thick for the new VMP 10-rib for rear-feed superchargers: VMP Gen3R, VMP Gen3, VMP Gen2R, VMP Gen2, VMP Gen1. Roush superchargers must have the snout and hub machined to accept a VMP 10-rib pulley. Spaces the supercharger pulley out .140", designed for the new VMP 10-rib kit and rear-feed Gen3R style superchargers (+1 rear +3 front over stock)Provides for the correct supercharger pulley alignment when used in conjunction with: ATI/ VMP 20% OD 10-RIB DAMPER FOR 2020+ GT500 5.2 L & 5.0 L VMP-918078And VMP 10-rib pulleys: VMP-24-10-B through VMP-35-10-B in .100" increments