Pen | Otho Fountain Pen Refill Cartridges
Otho black ink cartridges are refills for our Otho Dude Fountain Pen. They are standard international short size cartridges and are compatible with many different fountain pens. Each box comes with six cartridges.
- Cartridge is 1.5 inches long (39 mm)
- Outer diameter of the tube opening: 4 mm
- Inner diameter opening: 3 mm
- Tail end diameter of the cartridge: 7 mm