3"-8" dth hammer DHD, COP model 4"-8" quick hammer High drilling rate Low air consumption Quality products good ... qualith DTH drill bit, DTH hammer. Now we can supply 90mm-254mm(3.5"-10") DTH hammer, 340,350,360,380, COP44, COP54, COP64, COP84 , 3"-8" DTH hammer, 340 ... ,350,360,380 4",5",6",8" quick hammer ...