This is the original standard 3.5" pressurized refill ink cartridge that fits most of the Fisher Space Pens. The write out for this refill is approximately 15,000 feet (4.500 meters), depending on writing style - 3 times longer than a typical ball point cartridge!
The Fisher Space Pen Refills are sealed pressurized refills which do not leak, have a shelf life of over 100 years, write in a vacuum, upside down, under water and in extreme temperatures, in freezing cold and bitter heat. Give a whole new life to your favorite Fisher Space Pen, whichever model it may be.
