This overshoe is part of a pair that was made for astronaut training purposes prior to the Apollo lunar missions.
The International Latex Corporation made the boots which were part of Cernan's extra-vehicular (EV) equipment. The EV boots were worn over the boots that were integrated into the spacesuit and which included the pressure bladder and thermal coverings. The boots were made with a silicone sole, woven stainless steel uppers (Chromel-R), and included additional layers of thermal protection and beta felt in the soles as protection against extreme temperatures and sharp rocks on the lunar surface.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.