Colour-coded plastic cards with diamond grit abrasive surfaces. Suitable for moistened or dry use. For sharpening pocket knives, chisels, router cutters and small hand tools. Easy to transport and store. Fine, medium and coarse (360, 260 and 180 grit) grades. Colour-coded plastic cards with diamond grit abrasive surfaces. Suitable for moistened or dry use. For sharpening pocket knives, chisels, router cutters and small hand tools. Easy to transport and store. Fine, medium and coarse (360, 260 and 180 grit) grades.