These discs are specifically designed to handle the hard job of removing saw marks and grinding marks in order to prepare the stone for polishing. Ceramica Vitrified discs are ideal for the bullnosed or profiled edge, but also work very well on all curved edges. The vitrified bond is a compressed diamond impregnated pellet surrounded by plastic. This gives the disc a unique aggressiveness that is needed to remove difficult grinding marks. Available in 60, 150 and 300 grits.