NIB. The hooded nibs put down an even fine line. I tried several of them and they all worked well.
FILLING SYSTEM. There is no choice in filling system: your only option is the compression bladder. No cartridges are available that I am aware of. The bladder doesn't hold much ink and runs out fairly quickly. However, the pen is so small that I don't find it comfortable to write with for an extended amount of time.
QUALITY. Knowing what I paid for these pens, I was not expecting anything in terms of build quality. I was very surprised when I received them to see the consistent quality of the pens.
I purchased about ten pens in the three different finishes and only one had a defect, and it was minor.
RECOMMENDATION. The only other contender in this price range is the Pilot Petite, which is a fantastic little fountain pen. The Pilot Petite has a better nib and a wider girth but it is plastic. So, if you are looking for a very inexpensive and portable fountain pen that doesn't look disposable, you can't go wrong with this one. This would be a great starter pen for a child. And, for those of you who want to use only fountain pens for every writing opportunity, it is ideal for a travel journal or checkbook.