Uni-BallPower Tank Ballpoint Pen Black Ink Refills, 0.7mm, SNP7.24, Set of 6 (Japan import) [Komainu-Dou Original Package]

I bought these originally because I was looking for a Fisher Space pen type cartridge for my stainless steel pen body. Amazon brought these up as an alternative and I bought without doing more research. In the end I wound up buying the Power Tank pens and fell in love with their cost and use.These will only fit the Power Tank. Buying these keeps your Power Tank active and reduces overall waste. I would recommend. But be sure that you're not trying to fit these into any other pen body. It just won't work.

I write a lot of notes for work and this is the best pen I've ever used. These refills last a very long time and I highly recommend stocking up on them.

These are great pens because they're pressurized but not gloppy like Fisher Space Pens can be. The default cartridge for pens is always medium, but fine points are great for doing crossword puzzles and general writing. I press harder than I need to but this fine point doesn't rip through the paper. Also, you get more ink mileage out of them: Fine point = less ink per inch of writing. Yes, it's easy to just buy pens by the box, but imagine how much less plastic we'd be throwing out if we bought refills instead.

Writes in all temperatures as advertised, much needed for my job

love the pens, needed the refills. so far so good. i will definitely order more.

OEM part for the powertank pens. Best investment for lefties!