Dremel?? chain saw sharpening stone is for use with Dremel?? chain saw sharpener attachment. This replacement stone provides an excellent cutting edge on the chain saw's cutting tooth. Having a sharp chainsaw blade improves chainsaw performance and safety. Ideal for sharpening chain saw blades, quickly and easily Precision ground abrasive stone for quick, easy sharpening of chain saw blades Having a sharp chainsaw blade improves chainsaw performance and safety 3/16" chain saw sharpening stone BIT DIAMETER INCH: 3/16" BIT DIAMETER MM: 4.8 mm