DHD 360 hammer pressure down the hole hammer wind pressure:0.5- ... 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 with very good ... )15-34API(4 1/2)" REG195-254 Sell good DHD 360 hammer