Replacement refill for Fisher Bullet Pen

One of the best known pens of the 20th century - the Fisher Bullet pen. In 1948 Paul C. Fisher started producing the first pocket ball pen in the US. From 1968 onwards, Fisher developed, especially for NASA space missions, a hermetically sealed, pressured cartridge which prevented the ink from drying up (with the slogan ‘still writes after 100 years'). These pens are used by astronauts and cosmonauts. The patented cartridge writes in space, under water, upside down, on greasy surfaces and in temperatures ranging from -34°C to +143°C (may only be of theoretical interest). The cartridges are still tested by hand and integrated in the classical Fisher Bullet Pen. The gas pressure (3.5 bar) constantly presses the writing paste against the ball. This ensures a constant flow of the paste down to the last drop.