Dielectric Union are made up of Zinc plated FemaleNPT(BSP)Steel Adapter, Zinc Plated Hex Steel Nut,Brass Female NPT(BSP) adaptor, Plastic SleeveAnd Rubber washer. Size: 1/2 2" Rated Pressure: Unions 17 Bar(250psi) Rated Temperature: -40 Degree C to 110 Degree C Dry Flashover Voltage : 1500V Working Fluids : our unions are always suit for water and gas