The concrete engraving pin by Star Diamond is a solid (not coated) diamond segment ¼” in diameter by 1” long diamond router on an 1/8” shank. When used with a Dremel rotary tool it will score concrete, masonry and stone materials. In decorative concrete applications it is used to carve designs or extend score lines to the wall. For more information, contact Star Diamond at 800-282-6470.