This is an ink refill to replenish the ink in your favorite pen.
This gel ink ballpoint pen refill for your Style Fit pen body is ready to give you super-smooth writing with dense color--and it's waterproof, too! The Style Fit pen body also makes it fast and easy to install refills. This is a very fine 0.28mm size, with blue ink.
These gel ink refills come in lots of colors--you can find the complete list here!