White sharpening stone (Berkel # B9-00612SW) made in Germany for stainless steel blades of Berkel slicers 115, 180, 910, 915, D, E, F, FA and GS.
Proper knife sharpening is critical to slicer performance and should be done sparingly. Apply each stone for just a few seconds to restore a fine edge. Over-sharpening will burn the blade and the edge will be lost. Both stones (sharpening and truing) should be changed when a new blade is installed.