Zebra 0.5mm Black Gel Ink Refill (RJSB5-BK), for Zebra Multi Function Pen Shabo X Ballpoint Pen, × 5 Pack/total 5 pcs (Japan Import) [Komainu-Dou Original Package]

Great flow and smooth writing. These fit perfectly to replace a portable pen. Great value and worked better than expected. Will purchase again.

Since the hot topic with these refills is how they can't write for long, I wanted to objectively see for myself. I loaded this refill into a Zebra Techo T-3 Mini Pen and wrote in a 9.75" by 7.5" wide-ruled composition book until the refill died. I was expecting about 3 pages or so but was kinda blown away when I got just shy of 10 and a half pages. This is my first experience with D1 refills, and now I feel like they are kinda legit if you wanna carry a very small pen.

I filled 30 of 48 pages of my 3.5" x 5.5" Field Notes pad with one of these refills. The ink is smooth and much darker than the Uni Jetstream refill (SXR-200-05). I prefer this ink and will continue to use it in my pad

I like the bold, clean line that this refill leaves. It writes smoothly. I am new to D1 refills and was surprised by how little ink there is, but I understand that is the nature of the D1 refills and am not disappointed.

These pen refills write really smooth but be warned they don't last long!

These work great! I love the fine point and the look of the ink. They don’t last forever because they are small and made to fit certain barrels that can’t hold more ink. Love these!

I've been using these for over a year. My first one, I was surprised by how quickly it was spent but I read the reviews here and saw that these refills tend to have a short lifespan. I really like the smoothness of the ink so I figured I'd just put up with replacing it every 2-3 months. However, over the year, the duration of usefulness of these refills had gotten shorter and shorter. I've literally had to replace a refill twice in one day.My theory is that the short lifespan of these products have less to do with how much ink they have and more to do with how they are stored before shipping. I think they are getting clogged or dried out rather than emptying. I tried soaking the tips in alcohol and/or applying heat via a lighter/boiling water but this did not help.It may also be that the tips can pick up particles and get clogged really easily; I've noticed that certain rough papers seem to threat clogging the tip more.If it weren't for how short these refills last, I'd give the ink 5 stars. But I bought 15 refills a couple months ago and I'm almost out. Not worth it.

greatest writing instrument ever!!I love hand writing and this pen is the best . . . .but can't run down to the office store to buy. So finding it online is the greatest