This item is a spacer. But my countershaft bolt kept coming loose. It is the second one that I have bought and had the same issue with both. Worked better on my 05 Yamaha YZ than on my 07 CFR450R. The 05 YZ had a large nut V.S. the small bolt on my CRF. The first time it came loose I thought thought that maybe I forgot to torque the bolt down, so I cranked it down hard, still came loose.