The Spyderco Tri-Angle Sharpening Stones fit the Sharpmaker base and put an exceptionally fine scratch pattern on your edge for hair-popping sharpness. Each stone is 7" x 0.5" (178mm x 13mm). Use them dry, without oil, water or lubricants. For cleaning, scrub with a scouring pad and powered abrasive cleaner, then air dry. Autoclave safe. FeaturesFits the sharpmaker baseVarious grit options available