Combines 12'' x 3'' double sided diamond stone with a strong magnetic base that holds the stone in place. Stone has a continuous diamond surface. Fine 25 micron/600 mesh grit for a razor sharp edge and Extra fine 9 micron/1200 mesh grit used to polish and refine a razor edge after sharpening with a coarser diamond stone. Accommodates a variety of tools and blades. The magnetic base offers knuckle clearance for sharpening tools and knives. With the system it is easy to secure, change and remove the bench stone from the magnetic base for quick grit changes during sharpening.