Rapidair MAXLINE Compressed air piping tubing 1/2" UNION FITTING M8021 RapidAir MaxLine Compressed Air Piping 1/2" UNION Fitting M8021 FREE SHIPPING - FREE SHIPPING - FREE SHIPPING - FREE SHIPPING This Fitting is spefically desinged to be used with 1/2" Rapidair Maxline tubing. solid Nickle plated brass resists corrosion as the double O ring style will prevent leakage