Wheel bearing nut lock washer. This is the flat thin washer that goes between the the two wheel bearing nuts that gets bent over on the front axle.
Fits most Dana 27, 30, and 44 axles found on 1961-65 Scout 80, 1966-71 Scout 800, 800A, 800B, 1972-80 Scout II, Terra, Traveler or 1974-75 1/2 ton 4x4 IH Pickup or Travelall