Diamond Impregnated Rubber Wheel 3 Pieces Set: RD-W1, RD-W2, RD-W3 Set includes: 1 Coarse, 1 Medium and 1 Extra Fine wheel. 26 mm x 2 mm. Knife edge. Mounted on a standard 3/32" handpiece shank mandrel. Used on zirconia, porcelain and metals. Excellent for cutting, abrading, smoothing, removing scratches.Premium quality wheels.Your satisfaction is guaranteed.