This pressure bubble helmet was designed and constructed by the Hamilton Standard Company, and was a very early use of the highly impact-resistant material polycarbonate. The helmet enabled the astronaut to move his head within it, and a communications carrier was worn as well to enable him to communicate. Oxygen was pumped into the helmet through an opening in the back, which was a change from the previous system of a "spray bar" in the front. The newer system became the standard of oxygen supply for later helmets.
NASA transferred this to NASM in 1977
Transferred from NASA - Johnson Space Center