I recently purchased a 15 hp Suzuki online and it arrived with a 10/5 pitch prop on it which would not work on my 16 ft Alumacraft Jon boat ! I purchased 2 props from Deep Blue Yacht Supply a 91/4 /10 and a 91/4/11 not being sure which one would work the best ! I was able to buy 2 props because of their price , I also was very pleased with the speed at which they were shipped , really nice props and a very good company to buy from , will definitely recommend them !