Small parts for the dual motor contra-rotating F3P power system.
The two washer like rings support the spur gear on the outer shaft. The thicker one is installed between the prop and the gear, the thinner one on the other side of the gear. The third thickest part is a "drive washer" installed on the inner shaft, just behind the front prop.
Actual weight of the 3 parts together: 0.35g (black strong and flexible)
For more info on the motor system, please see: