This propeller works on the Vittorazi Moster but is NOT “Vittorazi Approved”, so you might loose your warranty on your engine when using this propeller. Using this propeller leads to a decrease of the RPM which is not recommended for the everyday Pilot. We only offer this propeller because there were dealers in the past who used this propeller. Out of fairness to our customers, we do not want to remove it from our range, although we always recommend following the recommendations of the engine manufacturer.