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