One of the Fisher Pen Company's original products and still available 50+ years later! The Non-Pressurized One-For-All Refill Breaks Down to all sizes to fit the pen that you have. It is made this way to fit several different pen barrels. If you need it to be shorter just flex it back and forth at the break point and it will separate leaving you the correct length refill. Fisher created the Standard Non-Pressurized refill to fit all pens and it comes in black and blue ink.
Fisher Space Pen - Refills - SO1F One-For-All Cartridge - Blue Ink - Fine Point Features: