The Ultimate in Sharpening Systems Technology is safe, easy, and convenient to use. Includes coarse (120 grit), medium (280 grit), fine (600 grit) and ultra fine (1000 grit) hones along with a medium triangle shape hone for serrated knife sharpening. This universal device, from cutlery sharpening company Lansky, is a two-piece mount that optimizes Lansky Sharpening Systems by providing a strong base and increased sharpening leverage. It's made of lightweight yet remarkably strong aluminium with a pre-drilled base. The entire unit stows in the included kit case for easy storage and transport, as well.