Cycle Visions Rear Wheel Pulley Spacers These spacers are made from 6061-T6 billet aluminum and are machined with a flange for perfect alignment. Features: .625 Thick Made from 6061 T-6 aluminum and features a machined finish Made to work with stock H-D aluminum hubs Flanged for perfect alignment May require longer bolts. Note: Will not work with Cush drive pulley.