Use our 600 grit aluminum oxide water stones for achieving an extra-fine edge on your blade. Unmounted aluminum oxide stones must be mounted to a “stone blank” (sold separately) to be utilized with the Edge Pro knife sharpening systems. Customers who go through many aluminum oxide sharpening stones can remove their worn out stones from the existing stone blank and mount their un-mounted knife sharpener stones themselves saving 50% off the mounted stone price. We suggest mounting the 600 grit sharpening stones using 3M’s Super 77 adhesive spray.