This propeller is perfectly matched to the Vittorazi Moster Factory R and standard Moster and is also “Vittorazi Approved”, so your warranty on the motor remains valid when using this propeller. This propeller is perfect for combining a medium frame with the extra Power of the Moster Factory R engine, whilst the specific profile of this propeller ensures adequate cooling of the engine at all times. Thanks to the large diameter, the performance of the Moster (Factory R) is perfectly implemented and gives you the extra power you expect while using this engine.