These are Fisher Space Pens ink cartridges with adapters for use in Parker Pens, and are gas pressurized to 35 PSI and hermetically sealed. The precision fit Stainless Steel, tungsten-carbide ballpoint and socket keeps them leak free and writing longer, cleaner, and more consistently. Take advantage of NASA Space Research. Why settle for an ordinary refill when you can have the same refills that have been used on every Space Shuttle mission, both USA and Russian. These are made by FISHER SPACE PENS in the USA.







