The Trend CRDWSF4FC is a 4 inch double sided diamond stone with folding handle and monocrystalline diamonds for fast clean stock removal which gives excellent sharpening performance It is double sided for coarse sharpening and fine honing Coarse 360 grit nom 40 microns and fine 600 grit nom 25 microns The Coarse is ideal for carpentry as it rapidly fixes or restores a damaged edge or blunt tools including chisels and plane irons The Fine is ideal for cabinet making for a fine finish and refines the cutting edges of chisels small knives etc - achieves a razor edge in seconds With plastic ABS folding handle that folds to protects diamond surface and oval holes design to collect and hold metal residue Ideal for saw blades chisels knives domestic and garden tools Recommended use with Trend lapping fluid to prevent clogging or rusting and assist in keeping tools clean