A cluster of genuine diamonds is mounted in a holder and used to dress or open the grindstone when the stone becomes grooved or glazed it takes only a few seconds to set up and can really improve the performance of the wheel dual knob screw permits an easily controlled feed across the stone for a perfect flat surface if you feed faster you can create a rougher surface which grinds more quickly mounts and locks instantly in the right position on the universal support of the tormek sharpening