This is a coarse, diamond impregnated stone that can be used for zircon as well as porcelain in the dental lab. The advantages of this stone are that is long lasting and it doesn't heat up the porcelain. The shank is made from solid stainless steel and available in handpiece shank diameter (3/32” / 2.35mm). The diameter of the head is 120 (12.0 mm). Made in Germany.