No offense but I call BS I have seen the part used myself and it is an exact replica of the impeller on the Marineland. Which model did you get the part for? I could ask my brother in law which model his impeller was from in case they are not all the same. Also which model Sunsun does your buddy have?
None taken, I have nothing to gain from bs'ng on a fish forum lol
He has the 302 and I'm pretty sure he tried the one from the 220
BTW he fixed the impeller shaft by going to a tool and die shop,
they got the specs and made him a SS shaft.
I don't really knock these filters I just think they use thin cheap plastic for the baskets and in/outs.
They are worth what you are paying for and nothing more, just MO.
And I don't own one but I have a first hand opinion, showing my bud how to clean the darn thing