... hole:two match hammer:3-8inch 90-203mm bit Good quality, low price Down hole rock roller bit With yeas ... thread button bit. Now we can supply 90mm-254mm(3.5"-10") DTH rock drill bits, 340,350,360,380, COP44, COP54 ... , COP64, COP84 , 3"-8" DTH hammer, 340,350,360,380 4",5", ... bitOuter dia. of pilot bitMatch hammerWeight(kg)183mm163mm188mm140mm160mmZRC130G60.3