Electric Grinding Sanding Drum Kit - 1/4" Shank and 1/8'' Shank - Drill Accessories Attachment Mandrel rubber shank diameter: 1/4'', 2pcs; 1/8'', 1pc 1 x 12.7mm(1/2'') sandpaper rubber rod; 4 x 12.7mm sandpaper rings 1 x 19.05mm(3/4'') sandpaper rubber rod; 4 x 19.05mm sandpaper rings 1 x 31.7mm(1-1/4'') sandpaper rubber rod; 4 x 31.7mm sandpaper rings 1/4'' shank on 4 middle drums and 1/8'' shank on 4 small drums