Types: male thread end, female Thread End, hose ends; Material: Malleable Iron or cast steel, size;3/8", 1/2", 3/4", 1" 1) Universal air hose coupling: a) Types: male thread end, female Thread Endb) Sizes: PT3/8, PT1/2, PT3/4, PT12) Nominal hose end of cast bronze air hose coupling: 6mm, 8mm, 9mm, 12mm, 15mm, 19mm, 25mm Air Hose universal coupling (U.S.Type & European Type)