Manufacturer of Mining and Quarrying Tools Extension Drill Tools(System): R22/R25/R28/R32/R35/T35/T38/T45/T51/GT60 A. Shank adapter + M/F Rod + Thread Bit B. Shank adapter + Coupling + M/M rod + Thread bit R25 (1") SERIES (Recommended bit diameter Dia.33~Dia.45) R28 (1 1/8") SERIES (Recommended bit diameter Dia.37~Dia.45) R32 (1 1/4") SERIES (Recommended bit diameter Dia.41~Dia.64) R35 (1 3/8") SERIES (Recommended bit diameter Dia.48~Dia.64) T38 (1 1/2") SERIES (Recommended bit diameter Dia.64~Dia.102) T45 (1 3/4") SERIES (Recommended bit diameter Dia.70~Dia.115) T51 (2") SERIES (Recommended bit diameter Dia.89~Dia.127) GT60 SERIES (Recommended bit diameter Dia.92~Dia.152)