PATIKIL 60pcs Fountain Pen Ink Cartridges 3.4mm Bore Diameter Pen Ink Refill Standard International Refill Cartridges for Writing Business Dark Blue

Specifications: Material: Plastic; Ink Color:Dark Blue; Ink Refill Size: 5 x 0.7cm / 1.97 x 0.28 inch ( L * Dia ); Inner Diameter: 3.4mm; Packing List: 60 x Fountain Ink Refill

Advantages: The smooth, quick-drying ink in these ink refills prevents smudging, ensuring clear writing and giving you a smooth writing experience.

The plastic shell is sturdy and shatter-resistant, which can effectively protect the ink inside; Ensure long-term use; The ink is pH-neutral, which can protect your pen and ensure safe daily use.

Instruction: For installation, remove the pen cap, pen barrel, and ink converter; Gently align the narrow end of the ink with the pen tip and press firmly until you hear a click; Once installed, gently shake the pen to promote ink flow and start writing smoothly.

NOTE: Please confirm whether it is suitable for your pen before purchasing, as they may not be suitable for all standard sizes.