The secret behind the Kaweco Sport fountain pen lies in its cap. The smart design allows the pen to cap compactly and post at the perfect length for writing. The silver-colored steel nib is available in medium. The cartridge filling system is easy to use with your favorite fountain pen inks. Requires short standard universal cartridges for refills (Pelikan Giant Ink Cartridges will not fit). Comes with one blue ink cartridge. Optional clips are sold separately. Approximate size as follows: Length Capped: 4.2". Length Posted: 5.2". Barrel Diameter: .4". Cap Diameter: .5".