This is a used Kenne Bell 3.75" 8-Rib pulley. It uses an 8mm bolt, not a 10mm bolt, so I believe it is for the older KB blowers. Has a slight cosmetic imperfection on the front edge, as in picture, but worked fine for me. Also included is a brand new 8mm bolt I bought direct from Kenne Bell. Please be sure this pulley is the right one for your blower, as I can't accept returns if it does not fit. Please LMK if you have questions. Asking only $48 shipped in the continental US.