... 90-203mm bit Good quality, low price Down hole rock roller bit With yeas of experience, now Zhongrui can manufacturer the best ... , 340,350,360,380 4",5",6",8" quick hammer with very good price and service. No.DescripationModelMatch hammerFront buttonsGauge buttonsBit ... .224 ZRQ203G-A 6-1826Q9-1826QConcave face, Concentric Casing System With Ring Bits ZRTG140Outer dia.of casing tubeInner dia.of casing ...