The Ultimate Edge 12-Inch Professional Knife Sharpening Steel is made with premium grade microcrystalline diamond. Ultimate Edge knife steels are bonded with nickel to a lightweight shaft that sharpens and realigns at the same time to produce a high-grade cutting edge. No messy oil or water needed. Lightweight and easy to use, the 600-grit diamond mesh also sharpens serrated knives. Dimensions: 12-Inch x 3/4-Inch