This pressure helmet was worn by astronaut William Anders during the Apollo 8 mission in December of 1968. Apollo 8 was the first lunar orbital flight of the Apollo missions.
The Apollo pressure helmet was a molded, polycarbonate shell with a bayonet base, bonded to the helmet neck ring, and was the male half of the suit neck-ring assembly. There were two configurations used on Apollo suits which were not interchangeable, the earlier configuration was anodized blue, with the later configuration being anodized red.
NASA transferred the helmet to the National Air and Space Museum in 1969.