This is a pressure bubble helmet for a spacesuit. This object is part of the Space Suit Assembly Extravehicular Mobility Unit (SSA EMU), which is the spacesuit and primary life support system that astronauts wear when performing spacewalks from the American port on the International Space Station. The spacesuit is designed to be reusable and adjustable with interchangeable parts to fit a wide range of astronauts. A version of the EMU has been in use since 1983 on board the American space shuttles. Over the decades, individual components of the suit have been modified and upgraded to improve astronaut comfort, mobility and safety. The Air Lock Company in Connecticut manufactured this helmet to specifications that NASA originally generated for the Apollo program in the 1960s. This helmet forms the pressure seal and on top of it sits an extravehicular visor.ILC Dover, the company that is the primary contractor for the SSA, transferred this item along with a large collection of other components of the spacesuit to the museum in 2013. Each item was used in testing or fabricated as part of new design efforts and bears the clear markings in red as "scrap" or lines through the label. ILC used these markings to assure that the objects would never be reused in testing or flight.