The CYCLONE ULTRA CORE BIT by Diamax is designed for use on: Engineered stone, granite, marble, porcelain, quartzite, and ultra-compact materials. Use WET or DRY on an an Angle grinder or pneumatic machine. Specific grit & bond composition provides a fast clean hole through porcelain & other ultra compact material. Featuring thin beveled segments for ease of entry into material. Shortened overall length for added control. Fitting: 5/8″ – 11 thread. Max RPM: 5,000. Usable Length: 2.25". Diameter: 1-1/4"