Mega Garden Post Brgc - Outdoor Light Fixture Support by Arlingtongard n post. 37" support for outdoor light fixtures or gfci devices outdoors. opennings on both sides of post for back to back power or power on one side and low voltage on the other. built in stablaizers need to assembly. opennings in stabalizers allow for insertion of extra support material. angle cut post for easy acces to unground wiring. two 1 2" knockouts. color brown. color is permanent, no chipping. optional extender, gpx18 adds 18" increments