Jointer / Planer Blade Sharpener Aluminum Oxide Knife Hone 180 and 400 grit in Wood Holder with Reversible Sharpening Stones KH-10AO Keep your jointer and planes knives factory sharp w/o removing them from cutterhead Perform several strokes along both the bevel and face of your knives and youre back to work Aluminum oxide 180 and 400 grit stones Sharpening stones are reversible