... coupling 1.size : 1",1.5",1.75",2",2.5",3",4",5",6" 2.type: American coupling, British coupling ,and others supply ... fire hose coupling according to your requirements 1. nominal diameter ... .material : aluminum ,copper5. size : 1",1.5",1.75",2",2.5",3",4",5",6"6.casting fire hose coupling resilient coupling