Product Description Dependable in Any Environment Fisher Space Pens sealed, pressurized refill cartridge writes in the most extreme conditions from -30F to +250F, underwater, in zero gravity, and at any angle (even upside down). Trusted by Professionals Chosen by ski patrols, search and rescue teams, law enforcement, and the armed forces, these refills are built for anyone who needs reliability they can count on. Long-Lasting Performance Each refill writes up to 12,000 feet, depending on style and surface far longer than the average pen. Versatile Compatibility Every pressurized refill includes a plastic adapter, making it compatible with most Parker-style pens. (Adapter dimensions: Length 1″ / Width 0.23″)