Adapter is use to mount Beacons & Globes to other poles. Strong Nylon Adapter fits in the End of the Fiberglass Flagpole, allowing Beacons & Globe Lights to be threaded into the Fiberglass pole, replacing Ball Top. The Adapter Plug pushes into the Top of the Fiberglass Pole then the threaded Stem will screw in. 1/2" -13 Thread.