Introducing Nano Hone's diamond resin bond disk with two different sizes. Like other Nano Hone diamond resin products, this 10 micron (similar to 1500 grit range) literally wipes away steel. Diamond is a much harder mineral on the Mohs scale. (Note : The Mohs scale of mineral hardness is a qualitative ordinal scale characterizing scratch resistance of various minerals through the ability of harder material to scratch softer material - from Wiki) Because the resin is soft, it acts like a lubricant, and you can use this disk wet or dry. It comes with tough adhesive backing that will stick to your motorized disk. This will fit any 6" or 8" disk with 1/2" center hole.