The Kaweco Sport Fountain Pen follows an original 1935 octogonal design. This pen is a compact size about 4.1 inches long closed and 5.2 inches long with the cap posted on the back. The cap screws on securely and stays on when in your bag or pocket. This pen takes a standard international sized cartridge, and comes with 1 blue one. This pen can only take Kaweco’s special mini converter if you want to use ink bottle. You can also get an empty cartridges and syringes from Private Reserve and fill those with bottled ink if you choose. Made in Germany.