This is a plastic fin assembly for a flying rocket model. As with fins on real rockets and missiles, the fins on a model rocket help guide it on the correct course after being fired. The manufacturer of this fin assembly, as well as what model rockets it could be used on, are unknown.
G. Harry Stine, an American pioneer in the field of flying rocket models, donated it to the Museum in 1973.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.