This is a late prototype of the Apollo spacesuit that astronauts wore on the surface of the Moon. The suit bears the designation A6-L, meaning that it was the sixth iteration of the spacesuit, one before the final, made by ILC Industries under contract to NASA. Astronaut David R. Scott used this spacesuit to train for his Apollo 15 mission. This suit differed from the one that he wore during his mission in a few ways. Most notably, Scott's A7-LB suit was redesigned so that the zipper went around the waist and no straight down the back. This allowed Scott to sit in the Lunar Roving Vehicle that Apollo 15-17 astronauts used to expand their exploration of the surface of the Moon.
NASA Johnson Space Center transferred this spacesuit to the museum after the conclusion of the Apollo program.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.