uni-ball Signo 207 Gel Pen Refills, 0.7mm Medium Point, Black Ink, 6 Refills

the ink in these work really well. they're 11 1/4 mm long. the use is very easy since the ink flows well, dries quick, and works well with left-handed people. i tried to place it in a kaco(another pen brand) pen but it didn't fit, so if you have multiple empty uniball pens, i recommend buying this. a bit on the pricey side for just ink refills but... it's a really good ink.

I had six pens needing a replacement cartridge. Each cartridge was a perfect fit and a welcomed find for the money spent. The refill quality, thus far, has been excellent. Most pens using this cartridge type historically for me have struggled with durability. Functionality has seemed compromised when one can see ink in the cartridge but the ink did not flow to the cartridge’s point.

I use the pen primarily for writing checks, since the type of ink cannot be altered by check thieves.

These refills worked perfectly in the pens that old ink had dried out. Easy to install.

Love this pen and refills.