Orbit 3/4" MNPT x FNPT 90 Degree Swing Joint Elbow. Made of heavy-duty, durable polyethylene, this elbow lets sprinkler heads be set in the vertical position for better spray coverage. It is ideal for use with PVC (polyvinyl chloride) and poly pipe systems, allowing free movement in any direction when connected to other components. Used to make swivel assemblies for sprinkler head risers. Not to be used under continuous pressure. For outdoor use with cold water only.