Atdec Pole Extension Kit For 54.7mm PolesThe ADM PX is an external joining kit for 54. 7mm poles which is designed to extend the drop of pole mounted installations. Made from a single piece of 4mm thick heavy duty steel, the joiner easily bolts to the outside of the poles to create a rigid join. The open tube design allows cables to pass through unimpeded and also provides a cable access point at the join location.