Uni Signo RT1 Gel Ballpoint Pen Black Ink Refills, 0.28mm, Set of 4

These refills are ideal. They go with the original pens perfectly. HOWEVER… make sure you match the pen I.D. numbers exactly as they are written. I made the mistake of looking too quickly when I bought the refills the first time around and got the wrong ones that did not fit. When I checked the packaging, the numbers were off by one. My fault. So, I made sure to check those identification numbers carefully. Now, I’m so happy with the product. Exactly what I needed.

Ink flows well even point is Very extra- fine!

Works perfectly in my Signo pen, which I love. Very "fine" ink flow makes writing in very small print possible, much to the consternation of people who try to read what you're writing while you're in a public place, lol. This refill is as stated in the product info: for Uni-ball Signo RT1 Gel Ballpoint pens; it is extremely easy to replace the old cartridge with the new one - just slips into the pen.

There isn't really much more to add. These pens are great, second to none. The fact that I don't have to throw away more plastic into a landfill when they inevitably run out is just the cherry on top! Buy this!

The refills are exactly like the original and they fit and write exactly in my pens as expected, no problems at all. Delivery was faster than estimated. All-in-all, I am totally satisfied and have already bought other items from this seller.

Great product

Good news: The tip is 0.28. Bad news: It's too wide to fit into the Uni-Ball Signo pen body. Compromise news: It does fit in a Uni-Ball One pen body. If you ordered this and have one of those, you should still be able to make it work. But yeah, it's a bizarre mistake, and I'm surprised Uni-Ball made an error like this. Hopefully, I'm the only one who experiences this, and everyone else gets perfectly fine pen refills.

Use care. Fits ONLY Uniball RT Signo retractable pen....not any Uniball Signo 0.28 mm pens. Advertised as refill for Uniball Sign 0.28mm. Misleading.