The sign pictured in the image reads:

When the supersonic B-58 Hustler entered service in 1961, it had individual ejection seats for its three crew members. However, ejection at speeds above 665 mph was extremely hazardous. To improve ejection survivability, the Stanley Aircraft Corp. developed a high-speed high-altitude capsule ejection system that would allow safe ejection at supersonic speed. The capsule was adopted for retrofit beginning in late 1962, making the B-58 the first USAF aircraft with a capsule ejection system. It was effective throughout the flight envelope up to 70,000 feet and twice the speed of sound.

The capsule has airtight clam shell doors and independent pressurization and oxygen supply systems, with survival gear packed inside. Raising a handgrip activated the restraint system harness securing the occupant inside and closed the capsule doors. The crew member could continue the ejection procedure and be catapulted upward by a rocket out of the aircraft by squeezing an ejection trigger or could remain encapsulated in the event of cabin pressure or oxygen loss until the aircraft reached a lower altitude. The pilot's capsule contained a control stick and other controls necessary to fly the aircraft while encapsulated. After ejection, a parachute lowered the capsule and shock absorbers eased the impact of the capsule on touchdown. The capsule floated if it landed on water and additional flotation cells could be manually inflated to provide stability on water, turning the capsule into a life raft.