if it's mendrel bent, I don't see how it would be more restrictive aside from the small bend at the beginning

 

I didn't really see how either. If I recall correctly, it has something to di with the "flex" section. Something about it reducing size at that point.

I'd have to check for sure, but I think Mahnaflow's part number is 24333. I still have the box, but its out in the garage.