This three stone sharpening system is ideal for quick, easy and effortless sharpening of any blade. The 70mm x 200mm metal stones are electroplated with monocrystalline diamond in three grits, 400G Coarse, 600G Medium and 1000G Fine Ideal for general purpose sharpening of knives, scissors, chisels, plane blades, cutting blades, TCT router bits and any tool that requires a sharp edge Diamond stones will sharpen carbon steel, HSS and tungsten carbide tools and may also be used to abrade glass, ceramic tiles and porcelain The benefit of these stones over a traditional abrasive sharpening stone is that the sharpening surface remains absolutely flat and will not ‘groove’ over time. This is essential in order to provide consistent straight edges on precision cutting tools such as wood chisels and plane irons The ABS plastic base has non-slip pads for use on most surfaces, and each stone can be removed to be used separately Can be used dry or with water as a lubricant, no oils are necessary