Sculptor's 400 grit 2pc Whet Stone Set. Useful in sharpening a wide variety of chisels, scissors, knives, blades, etc. The large stone measures about 4 1/4 inches long by 2 9/16 wide by 11/16 inch thick. It has a Flat Side and a side with concave grooves that are 3mm, 6mm, 7mm, 11mm, and 12mm wide. The small stone measures about 2 5/8 inches long by 1 3/8 inches wide. It has rounded edges with thickness on one side about 3/16 inch and 9/32 on the other side like a wedge.