... "; Name: USA Industrial Type Air Couplers, Milton type(Air Coupler, Air Tool Coupler, Quick Fitting); Body size: 1/4", 3/8", 1 ... size: 1 / 4", 3 / 8", 1 / 2"; Coupler type: Milton type, Industrial type; Surface treatment: Zinc plated, acid washing; Working pressure: No ... will be strictly tested for its working pressure, air leakage, surface finishing and thread test. Industrial Coupler