The VMP 100 mm idler pulley is designed to reduce belt slack and increase supercharger pulley belt wrap when utilizing a smaller supercharger pulley.
VMP Performance 100mm Heavy Duty Billet Aluminum Idler Pulley - 6/8/10Rib
100mm Idler Pulley for use with Smaller SC Pulleys
VMP Supercharger Pulley
Supercharger Pulley