The Eastwood Contour SCT® Finishing Drum is to be used in light paint or rust removal applications or when finish surfacing bare metal. Each drum is 4 inches wide and 4.5 inches in diameter. 40% more abrasive material than the original SCT Abrasive Drum for longer life. Non-Woven Nylon/Aluminum Oxide Finishing Drum with Molded ABS Plastic Hub 240 Grit Fits 3/4″ Keyed Shaft 4″ Wide 4.5″ Diameter Max RPM 4000