Sharpening stone (abrasive grinding wheel), 51 mm diameter, coarse grit, for RGV meat slicers. Wear part of the built-in sharpener assembly that restores the edge of the circular blade with every sharpening pass. The coarse grit removes more metal and rebuilds the cutting edge on worn or nicked blades: it is the first wheel in the cycle, completed by the fine grit (51 mm fine-grit version) for finishing the edge. Keep both grits and replace the stone when it is worn. Check the diameter (51 mm) and the mounting on your RGV model before purchasing.