On July 24, 1969, at the end of its historic Moon landing mission, the Apollo 11 command module Columbia splashed down in the Pacific, about 24 kilometers (15 miles) from the aircraft carrier USS Hornet. Navy swimmers jumped from a recovery helicopter into the water near the command module to stabilize it. They attached and inflated around it a custom-made flotation collar. To the flotation collar they fastened a large, seven-person raft. The astronauts donned special Biological Isolation Garments and then emerged from the spacecraft and climbed onto the raft in preparation for their transfer to the Mobile Quarantine Facility on the Hornet.
This collar attached to the "egress trainer" command module is the actual unit deployed during the recovery of Apollo 11. It was transferred from NASA to the Smithsonian in 1977.
This object is on display in Human Spaceflight at the Steven F. Udvar-Hazy Center in Chantilly, VA.