Pen Uno is an extremely minimal pen designed to be both a pleasure to write with and beautiful to look at. At only 5.3mm (7/32in) in wide, it is one of the slimmest pens ever manufactured, yet it is very comfortable to use because its holding barrel is slightly wider. This barrel also serves as a twisting cap that protects the pen tip when not in use. Pen Uno is precision-machined out of space-grade aluminum and anodized in four distinct colors: space grey, silver, gold, and rose gold. Pen Uno uses the widely available Hi-Tec-C Coleto gel ink cartridge. This cartridge writes exactly the same as the regular Hi-Tec-C cartridge but it is much slimmer in diameter because it was designed for a multi-color pen system. Taking advantage of this super slim cartridge, the designers were able to construct what is one of the most minimal pens ever designed.