HongDian Fountain Pen Ink Converter, Pack of 5, 3.4mm Bore Diameter

• Compatible with fountain pens take 3.4mm cartridges such as hongdian
• Simple plunger action mechanism draws bottled ink with a simple twist
• Length: 71mm, Bore diameter: 3.4mm
• Package: 5 PCS fountain pen converters

Instruction on how to fill your fountain pen with converter: 1) Insert the end of the enclosed converter with the open ring into the back of the section block with enough pressure to create a snug fit. 2) Twist the end of the converter to send the piston down to the end inserted into the section block. 3) When you fill the pen at the first time, twist the converter anit-clockwise to make a few drops of ink coming out of the nib, so that it can flow easily. You can also refer to the video instruction here: https://youtu.be/T8mfof7ZpU8