NEW! Tools4Boards HONE DUO 400 Grit Medium Side is the perfect all round maintenance and polishing stone for sharp, smooth edges. Typically used as the third stone in progression from X-Coarse to X-Fine grit. 800 Grit Fine Side is the perfect first stone for final polishing after edge bevel and sharpness have been established. Typically used as the forth stone in progression from X-Coarse to X-Fine grit.