Features:

• These cartridges are not standard size. The bore diameter is 3.4mm which is compatible with Yongsheng Fountain pens
• With no break in ink flow, enjoy a smooth and optimal writing experience as your fountain pen glides elegantly across paper.
• The ink has been carefully manufactured using only natural dyes giving the composition a neutral, natural, and non- toxic pH.
• Package : 10 PCS Blue Ink Cartridges
• Dimension: About 5 x 0.7mm, Bore diameter: 3.4mm

Description:

• Comes with a case: portable and convenient on-the-go
• Kind reminder: these cartridges work in most fountain pens, however please check the dimensions of your pen before purchase
• Get blue ink in one pack
• Smooth running ink and easy to install