Can I use third party propellers on the Alta 6 or Alta 8?

No. Only use original Freefly Alta propellers found here: Clockwise and Counterclockwise.

The motor drives on the Alta are not like standard off the shelf ESC’s. The drives are tuned specifically for the combination of the F45 motor and the Alta propellers. The weight and inertia of every propeller is different, and thus requires specific tuning.

Using propellers other than the stock Alta ones, can lead to motor failure and a crash. This happens because the motor drive can lose sync with the motor if a non-standard prop is used.