Triple action pen refill.
Fisher pressurized small diameter (.92")
These refills are for made to fit most 2 & 3 colour pens, just snap the refill via the indents to the required length
The Refill fits
This is a very small refill holding little ink so it wont write very far. However while it writes its very dependable.
It uses the pressurized refill technology invented by Paul Fisher for NASA. Its used on all manned Space Flights, because it writes in the freezing cold, boiling heat and gravity-free vacuum of Outer Space
