The Mark IV - Arrowhead Pressure Suit was developed for pilots in the United Stated Military.
After learning about Wiley Post's accomplishments of flying faster in the jet stream, the U.S. Navy enlisted B.F Goodrich to make them a pressure suit for their pilots. This enabled their pilots to reach higher altitudes and faster speeds.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.
Equipped with zippers, flexible fabric, a pressure gauge on the thigh, and hose connectors on the lower left and right torso, Navy pilots had a much bigger range of motion.
The U.S. Air Force also authorized production of the U.S. Navy Mark IV for squadrons stationed in colder areas. It was tested to altitudes of 139,000 feet, and demonstrated its ability to overcome the problems associated with emergency ejection, immobility and manual pressurization.
NASA obtained this suit from the Navy for evaluation and testing purposes. NASA then transferred the suit to the Museum.
Navy Pilots tested the flexibility of the Mark IV pressure suits as a demonstration for the spacesuit. The final score of the baseball game is unknown, but the Mark IV would evolve to become the original Project Mercury spacesuit, a definite home run!