They also disclosed that Cooper had chosen the older of the two primary parachutes supplied to him, rather than the technically superior professional sport parachute, and that from the two reserve parachutes, he selected a "dummy", an unusable unit with an inoperative ripcord intended for classroom demonstrations, although it had clear markings identifying it to any experienced skydiver as non-functional. (He cannibalized the other, functional reserve parachute, possibly using its shrouds to tie the money bag shut, and to secure the bag to his body as witnessed by Mucklow.) The FBI stressed that inclusion of the dummy reserve parachute, one of four obtained in haste from a Seattle skydiving school, was accidental.