Pilot Hi-Tec-C 04 Gel Ink Pen, Ultra Fine Point 0.4mm, Blue Ink, LH-20C4, Value Set of 5.

I write small. Therefore, I love super fine pens. This pen is the best "below 0.5" pen I've used. I heard a ton about these in my quest for smooth very fine pens. They did not disappoint! Pros: THIN LINES -- The ink flow is thin enough where my letters don't simply look like little blots of ink on the paper. NOT SCRATCHY -- Most pens 0.4 and below begin to get very "scratchy" while writing. The smoothness disappears and it does not feel nice to write with. Not these though, these are AMAZING. They are just as smooth as any other pen I write with SOLID LINES -- the ink flow does not skip like some competitors I've tried, just nice and smooth Cons: ERGONOMICS -- One thing I am not crazy about is the feel in your hand. They are super light and feel a bit cheap. While that's not really a big deal if they write the way I want, if your hands require a grip, these might be trouble for you. I was able to add a grip to the one I'm using now and that made a big difference but then you cannot put the cap back on... if these had a grip, they'd be near perfect. DESIGN/MATERIALS/LOOK -- Same as above, TOO light and plastic therefore feels cheap. I guess the look is a subjective thing, but I much prefer the look of other Pilot pens. FRAGILE TIP -- this one is to be expected given how thin the tip is... just be careful not to drop it. I dropped one and the tip bent. It was only a 6" drop from my hand onto my desk and just like that, the pen is useless. Just be careful handling them and you should be fine. Overall, while there are some cons to the design of this pen, the writing experience is still unbeatable if you like super fine pens. Grab a set, they are worth it if you can get over the poor aesthetics and ergonomics.

The BEST pens, fine point, writes so smoothly.

best pen ever. silky smooth

These pens are amazing. I struggle to find the perfect pen for my office job. I like a gel pen but often that means thicker points and smudges. These are ultra fine point and write beautifully!!!

The line is indeed 0.4 mm. The ink flow is consistent and leads to consistent writing. These pens are now permanent choice for handwriting notes.