... , COP model 4"-8" quick hammer High drilling rate Low air consumption Quality products good price With yeas of ... experience, now Zhongrui can manufacturer the best qualith DTH drill bit, DTH hammer ... we can supply 90mm-254mm(3.5"-10") DTH hammer, 340,350,360,380, COP44, COP54, COP64, COP84 ... ,360,380 4",5",6",8" quick hammer with very good price and service. No. ...