XMS23DSHARP Faithfull Diamond Sharpening Stone is ideal for quick, easy and effortless sharpening of any blade and many other tools. Its double sided 8mm thick metal stone is electroplated with monocrystalline diamond in two grits, 400G Coarse & 1000G Fine – both of which can be easily accessed by simply releasing the stone from the docking station and turning it over.