Rain Bird 21186601 1-1/2" NPT Outlet Elbow for Swing Joint Assembly - This NPT Outlet Elbow is for use with the Rain Bird Swing Joint Assembly. Rain Bird Swing Joints are designed to deliver the performance you expect while saving you money with their superior flow characteristics and excellent structural integrity. Available in a wide range of configurations, Rain Bird Swing Joints are the perfect complement to our golf series rotors.