This is Sullivan 1/4 Scale Double Rudder Control Horn. Suitable for pull-pull setups on rudders and elevators on all Large R/C airplanes.
Heavy Duty glass filled nylon horn, and an Anodized Support base. Comes with 4 in. threaded 8-32 stud that threads all the way through the control surface. Horns are independently adjustable for control throw. Comes with a .750 in. (19mm) offset, to permit mounting away from the hinge line.