Zebra 0.4mm Blue Ink Refill (JF-0.4), for Zebra Sarasa Clip 0.4 Gel Ballpoint Pen(JJS15-BL), × 5 Pack/total 5 pcs (Japan Import) [Komainu-Dou Original Package]

It's very slick and super fine, compares to Uniball 0.38 gel or 0.5 ballpoint.

Compatible with Sharpie S-Gel pens. I know these aren't gel ink refills but the size is perfect for the nice Sharpie s-Gel pens. I became addicted to using the white Sharpie S-Gel pens at work (I'm the only one there who uses them) but I can't find Sharpie refills at the point size I like. The 0.5 gell ink that comes with the white pens is too big of a point for the small boxed forms I need to write in (and the ink smears on plastic bags I need to write on), so these 0.4 regular ink refills are perfect. This is my 2nd time ordering them and I have the item saved so I can keep buying them (I go through a LOT of writing in a month lol).

Smooth writing ink for my refillable pens. Great fine line for writing. Prefer to use refills than disposable pens.

I made a mistake and bought this replacement for Zebra Multi Function Sarasa 4 Plus S Black/Red/Blue/Green Ink 0.4mm Ballpoint Pen, 0.5mm Mechanical Pencil, Black Body (J4SAS11-BK) . Fortunately, this refill fits Pilot Juice 0.38mm Gel Ink Ballpoint Pen, Black (LJU-10UF-B) , so I will keep it. By the way, the replacement for the Zebra Multi Function Sarasa 4 Plus S Black/Red/Blue/Green Ink 0.4mm Ballpoint Pen, 0.5mm Mechanical Pencil, Black Body (J4SAS11-BK) . are 10pcs Zebra Sarasa NJK-0.4 0.4 mm Gel Ink Multi Pen Refill (Box Set) - Blue Ink

The best writing pen out there.

I have ordered several refills for my refillable pen, but they have been sporadic as to whether or not they work. When I received these, they worked great. I like the line (the more narrow lines) and I can tell that I will get to use all the ink from each refill so this should last me a while.

It fits the TUL pen, for which TUL doesn't sell refills, perfectly. You just need to re-use the spring that came with your TUL pen TUL Retractable Gel Pens 0.5 mm Fine Point, Blue 12/pk . So don't throw away the old ink cartridge until you get the replacement loaded and have re-used the spring. 1. Unscrew the bottom silver tip. 2. Remove the old cartridge. 3. Remove the spring from the old cartridge. 4. Transfer spring to the new cartridge. 5. Load cartridge with spring into the pen. 6. Screw the bottom silver tip back on. Note the same series of refills fits the same series of TUL pens.

Really enjoy the writing of these refills and the sarsa clip pen. The color is more of a blue black vs a true blue and still writes very smooth. There was one refill cartridge that I received that was actually black vs blue. Checked the number on the side of the cartridge and it was correct. Thinking something was mistaken during manufacturing. Not a big deal. It takes quite a while to go through one ink cartridge and I use a pen for writing everyday. Blue (Blue Black) ink number = 1608. Black ink number is 1605.