Hey yall, I'm fairly new to boating and so far I can tell you that it has not been a cheap venture. This prop is to replace a factory prop on my 40hp. Johnson. The lower unit failed on the second trip after my maiden voyage , to make a long story short the original prop had been installed without grease or never seize so after many attempts to remove the old prop I had to burn the hub out ! When I learned of this new prop it was a no brainer, this was to be the answer to any future prop needs. Thank you very much for promoting such a great idea in prop design. I will be a returning customer .