Diamond Hones are good for touching up your tools and are more economical than CBN hones. They are preferred for sharpening carbide and these are especially good if used in conjunction with my technique for sharpening carbide cutters using your lathe. See video below. This is not a wimpy paper thin credit card size hone. Rather this is about 5.25" x 3.25" and a full 1/4" thick. It is 350 grit on one side and 600 grit on the other. The grit is embossed on each side so you can easily identify the grit you're looking for. This hone comes in a plastic pouch for safe keeping.