This adapter is also known as an angle crank adaptor. It can be used on a water fed pole or any cleaning pole with euro threading.
This is also used as the angle adaptor for the Elite Multi Tool Connector. (as pictured) All brushes and cleaning tools are sold separately.
This angle adaptor is euro threaded on each end. When fully straightened it is 5.5" long. Because the pole end of the adapter threads the pole inside the adapter is considered a 4" adapter because that's the actual extra extension length you will get.