... union fittings 2.good sealing 3.engaged in this line of more than 10 years 4.cheaper price 5.honest Material plastic ... experience.Provide: pneumatic components, such as union fittings .Primary Competitive Advantages: 1) Passed ISO ... as copper, carbon steel, stainless steel, plastic ect .6) Surface Treatment: galvanized, anodized ... since 1995. commonly used black plastic three directions union fittings