This Fine Grit ceramic stone is a replacement item for the ones included in the 204MF Tri-Angle Sharpmaker sharpening system. 7" x .5" (178mm x 13mm) 204F stone is sold individually and fits into the 204 Tri-Angle Sharpmaker sharpening system. For cleaning: scrub with a scouring pad and powered abrasive cleaner, air-dry. Autoclave safe.