... Co., LtdPDC bitMain TypeBit Diameters5 7/8",6",6 1/2",8 1/2",9 1/2",9 5/8",9 7/8",12 1/4", etc.Body ... TypeMatrix or SteelBlades2~9 Wings.Cutter Sizes5/16 ... "(8mm),1/2"(13mm),5/8 ... mining, explorer well drilling. Double row of teeth API 8 1/2" kingdream PDC bit