Thin-Flex Diamond Discs provide a high-caliber cutting on ceramic and composite materials. The diamond crystal sheathed edge contours and molds every surface type, including embrasure, and does not produce black marks throughout carving procedures. Thin-Flex X927-7 (0.15mm, 45 micron) Double-Sided Diamond Disc with Mandrel, 7/8", 2/Pk. Outside diameter: 22.2 mm.