The pivoted wood, metal, or plastic arm which converts the motion of the control lines to up-and-down movement of the elevators in a control line model aeroplane.

L-shaped white plastic piece inside all Palmer semi-automatic grip/trigger frames. Pushed by the Timing Rod to lift (and operate) the 4-Way Valve. Also called "Monkey Arm."

Steering mechanism used in most RC vehicles that consists of two posts joined a link. Each is connected to a left or right steering knuckle with a turnbuckle with one post connected to the steering servo.