Telescopic hangers have a central pipe clamp that lets the bar at its center slide up and down as needed from a pipe or grid. All hanger pipes terminate in female 1/2"-13 thread. This Matthews 5/8" Pin with 1/2"-13 Thread for MSE Telescoping Hangers has male 1/2"-13 threads to work into the female threads and a 5/8" pin to which the gear is attached.