Drum Sanding is used for smoothing the inside or outside of curved edges on project workpieces. This 1-1/2 Inch Dia. Shopsmith Drum Sander is 2Inch long with a rubber expansive drum that can be attached quickly to the spindle on Your MARK, Shopsmith Power Station, or the auxiliary spindle on your Shopsmith Belt Sander. Sanding Sleeves sold separately.