Njoy ordered

I had a rip off and decided to get a genuine on as the rip off is clearly got some sort of plating The thing is the rip off was 25 mm and 35 the genuine one is 24 mm and 44 I can manage the big end of the rip off the big end of the genuine seems a lot bigger Too big a step in one go loads of lube ?? Quite new to all this any thoughts? Cheers