... are distributed in the depth of impregnated bit's matrix series. The matrix layer of the crown contains a uniform distribution ... to be drilled. When order, please read .Size Available: "Q" series:AQ,BQ,NQ,HQ,PQ/AQTK,BQTK,BQ3,NQ2,NQ3 ... ,NQTT,HQ3,HQTT,PQ3,PQTTT2 series: T2 46,T2 56,T2 66,T2 76,T2 86 ... ,T2 101T6 series: T6 76,T6 86,T6 101,T6 116,T6 131 ...