-Uses the standard Fisher Space Pen 3 ½ inch Pressurized Cartridge
-Lasts 3 ½ times longer than a typical ball point cartridge
-Can write anywhere from the ocean to outer space
-Leather Pen Sleeve starts out tight but relaxes to the perfect fit with use
-To replace the ink well, you unscrew to top, then unscrew the pen grip, at the bottom of the pen grip is a set screw. Unscrew that, then some pressure may need to be applied to the ink tip to push out from top to bottom. Slide new Fisher Space pen ink in then screw back the set screw until tight.
3 ½ inch Pressurized Cartridge