I bought two of these propellers as a replacement for my Durafly Spitfire mk.IIA. The blades are .25 inch smaller in diameter but have the same pitch. I needed to adjust the spinner of the Spit but no problem. The prop needs balancing but it performed very well during flight testing. It also survived two "nose overs" after the landings on our very wobbly grass strip. I bought to to have spare one and I am happy with them so far and they look good!