Fisher Space Bullet Pen has the ability to go anywhere and write anywhere. When closed, the pen is perfect size to carry in your pocket, bag or toolbox. The cap posts on the end of the barrel to make for a comfortable, well balanced writing experience. What makes the pen unique is its pressurized cartridge that is capable of writing upside down, underwater, at extreme temperatures and, well, in zero gravity. The original Bullet Space Pen was conceived in July of 1948 and it is cited as an outstanding example of industrial art. NASA have been using the pens after rigorous testing in 1967. Even today, astronauts and cosmonauts use these pens for writing in the orbit. Extremely durable Compact size Pressurized cartridge Please note: Raw Brass model ships polished but will develope patina over time, as shown in the product images.