Pilot LP3RF Juice Up Mine

Personally I believe that this refill does the job well. You can easily move it in and out of the pen when you need to replace it.

My only concern is that in the first couple of weeks after replacing the refill the ink has issues with coming out, and the pen writes in a kind of strange manner where it doesn’t easily get on the paper.

Other than that, I would definitely buy it again for my gel pen. I have accepted that the little rough start is necessary for a smooth and satisfying flow later that lasts a couple of months with frequent use.