Coilhose Pneumatics 14-04BS ARO Ball Swivel Connector, 1/4-Inch, Male
Ball Swivel Connectors combine the features of Ball Swivel Fitting and Connectors, eliminating the need for an additional fitting.  These fittings provide a more natural range of motion than "traditional" air tool swivels while minimizing user fatigue and increasing working safety.  The connection and nut portion are Nickel plated hardened steel and the thread portion is brass.