Fisher SPR4F Ballpoint Refill Fine Black
The Space Pen pressurized refill features a tungsten carbide ball encased in a steel ball socket that prevents leaking and is designed to almost perfection. Pressurized at nearly 35 pounds per square inch so that ink is continuously fed and contains a visco-elastic, thixotropic solid-gel ink. With approximately 12000 feet of ink based on write-out machine testing, lasts 3 times longer than typical ballpoint refills.
- Comes with plastic adapter which fits any Parker style ballpoint pen
- Fine 0.5mm