This specimen is a fragment of titanium from SR-71- 61-7956, also known as NASA 831. With 1,454 successful flights and 3,967.5 flight hours, this craft holds the record for the most flight time regularly soaring above 80,000ft at speeds greater than Mach 3.2. It is also believed to be the single most photographed Blackbird aircraft. The material comes from the overlapping flaps which surrounded the exhaust of the SR-71, also known as a "turkey feather". Opening and closing according to the pressure output of the afterburner, they are considered one of the hardest working parts of the aircraft. The size and shape of the fragments will vary and some will show scorch marks from early preparation of the material.