Scarce X-15 pilot backup oxygen supply backpack for the MC-2 pressure suit, measuring approximately 17.5 x 20 x 3, consisting of the backup oxygen tank, tubing, and regulating devices made by the Firewel Company. Contained within a heavy duty silver cloth cover with buckles on one side. In fine condition. The X-15 was designed with a sophisticated ejector seat that allowed safe pilot ejection at speeds as high as Mach 4 and altitudes up to 120,000 feet. This backup oxygen pack was activated as soon as the pilot pulled the ejection handles and provided enough oxygen for about twenty minutes. A parachute pack was also integrated into the suit and attached to this backpack. This pack features the distinctive silver aluminized fabric outer layer used in spacesuits through the Gemini program. Although the MC-2 suit was only used on sixteen X-15 flights, it represented a breakthrough in suit technology and served as a model for spacesuits of the future.