Fisher Space Pen rose to prominence when founder Paul Fisher invented a retractable, pressurized pen called the Anti-Gravity 7 (#AG7) that worked flawlessly in zero gravity aboard the first manned Apollo mission in 1968. Five decades later the company continues to thrive with pens still flown aboard every manned space flight.
Black Ink Medium Point Space Pen Pressurized Cartridge Ballpoint pen refill fits most of the Fisher Space pens.
The Write Out for this refill is approximately 4.5km, depending on writing style - 3 ½ times longer than a typical ball point refills.
It can write in space, underwater and upside down.