This is an original foam core and cardstock model of the Rebel Bunker on Endor, created for the production of Return of the Jedi. This piece was built by the Art Department in the UK on the film, and then sent to the US to be used as an aid in constructing the full sized set. It is more detailed than the final set wound up being, and is very well constructed. Original foamcore set models from these films were mostly discarded, and very few exist today.
More from Star Wars: Episode VI - Return of the Jedi (1983)