This is a developmental version of the Apollo A7-L spacesuit that men used to walk on the Moon. This particular suit was sized to astronaut John Swigert, but consists of a pressure garment assembly (PGA) made to fit him and a Thermal Micrometeoroid Garment (TMG) coverlayer that fit astronaut Edgar Mitchell. The suit was made in 1968, most likely as a final test of refinements made before the first Apollo missions.
NASA transferred this spacesuit 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.