【Size Standard】2-1/2 NST/NH Female x 3/4 GHT Male brass hydrant adapter size : 2-1/2'' NH / NST(National Standard Thread) for attaching to fire hydrant; 3/4'' Male GHT (Garden Hose Thread) for connecting to a hose 【Easy to Use】Pin lug designs make the fire hose fitting connect and disconnect easily, greatly improve the work efficiency. Besides, the fire hose adapter would not rotate with hose is moved, will not loosen or break 【Premium Brass Material】The hydrant adapter is made of high quality solid brass, compared to other material hydrant adapters, the Boltigen hydrant adapter is more durable and strong. With corrosion resistance, ductility at high temperatures, and low magnetic permeability, etc advantages 【Wide Application】The fire hydrant adapter generally can be used for hydrants, fire trucks, garden hose and other water sources, etc 【Great Service】If you have any question about the fire hose & hydrant adapter, please let us konw first time, we must give you a satisfactory solution