True-running with no wobble or bounce, this high-quality drum delivers better control. Change belts in seconds for lapidary or metalworking tasks such as sprue removal and contour sanding.Angled expansion slots through the heavy rubber rim allow the drum to expand when rotated; thereby locking the belt in place. Belts can be quickly changed by stopping the machine, slipping of the old one and sliding on the new. In use, the resilient drum surface flexes to the gemstones contour to quickly remove grinding flats. The convex shaped drum provides the cutting action necessary to remove scratches. Sold without belt. The drum expands as the wheel rotates to hold the sanding belt firmly in place. The slightly harder-durometer rubber reduces cupping. Maximum recommended speed is 1800 RPM. CAUTION: Do not run the drum without belts in place as damage to the rubber rim may result.