Features: 1. This fountain pen refill slides smoothly on the paper, you will write fluently and the replace the ink cartridge can help you to save a lot of trouble. 2. The ink takes only a few seconds to dry ensuring your important writing record are not ruined by smudges. 3. Perfect for school, work, or a Christmas gift. 4. With no break in ink flow, enjoy a smooth and optimal writing experience as your fountain pen glides elegantly across paper. 5. This fountain pen ink cartridges lends expression to any writing or drawing ideal for calligraphy, taking notes in a journal or diary, and official business. Notice: *Actual color may be slightly different from the image due to different monitor and light effect *Please allow 1-3cm deviation due to manual measurement Description: Inner diameter: 2.6mm Weight: 80g includes: 50 pcs x Fountain Pen Ink Cartridges