Name: USA Industrial Type Air Couplers(Air Coupler, Air Tool Coupler, Quick ... Body size: 1/4", 3/8", 1/2"; Name: USA Industrial Type Air Couplers, Milton type(Air Coupler, Air Tool Coupler ... plug, push on hose barb; Material: Brass, steel; Thread size: 1 / 4", 3 / 8", 1 / 2"; Coupler type: Milton type, Industrial type ... working pressure, air leakage, surface finishing and thread test. Industrial Coupler