size of aluminum guillemin coupling: 1 1/2", 2", 2 1/2", 3", 4" material of coupling: aluminum size of fire hose: 1"-4" fire hose with guillemin couplingsize of aluminum guillemin coupling: 1 1/2", 2", 2 1/2", 3", 4"size of fire hose: 1"-4"we have double jacket fire hose, single jacket fire hose, red color fire hose and so on. fire hose with guillemin coupling