Space Pen
The Space Pen was invented by Paul Fisher and sold by Fisher, USA. Also known as zero-gravity pen. The pen is equipped with an ink cartridge pressurized to about 3.4 bar nitrogen and can be used upwards as well as in zero gravity, providing ink at any angle. Not only in water, but also in extreme temperature environments and used in wet paper. Currently, Fisher's space pens are readily available to the general public and are available in thousands of different sizes.