The original nib was too broad for my taste. Since I have a brand new 'MEDIUM' Knox K35 German nib handy, I removed the original nib and installed the Knox nib. It was just friction fit. The Knox nib is even smoother than the Jinhao nib. It's smooth as glass. The ink flow can be easily adjusted by just moving the nib in (wetter) and out (dryer) from the section, while keeping the feed at the same place.