A double sided credit card size diamond stone monocrystalline diamonds for fast clean stock removal excellent sharpening performance double sided for coarse sharpening and fine honing coarse 360 grit nom 40 microns and fine 600 grit nom 25 microns ideal for fluted shaped small router bits carbide or hss turning tools chisels plane blades carving tools all general tooling recommended use with trend lapping fluid to prevent clogging or rusting and assist in keeping tools clean whats included1