This type of circlips are famously used in drone motors for holding the central shaft from coming out of the motor. They are tiny and can easily be lost if you have ever tried repairing any. 

Measure the drone motor shaft diameter (not the groove) and buy the right size circlips.

If you are not sure, plz contact us before placing the order.

1X E -Type 7mm Drone motor shaft locking circlip (10Pcs.) pack