cobee 50 Pieces Fountain Pen Balck Ink Cartridge, Fountain Pen Ink Refills for Calligraphy Pen 2.6 mm Bore Diameter(2.6mm)

Works well. Put into a Kaweco Student pen. Punctured easy. Feels loose but not leaking. Placed the empty refillable cartridge behind it to keep pressure on it. Nice black ink, good deal on a multipack. 2.6 bore for Kaweco, Cobee, Jinhao pens.

these are nice and I like the fact you get so many. They are easy to change without a mess. they just push in kinda hard but once they pop and connect they stay in place, there was no leaking. I only wish that they came in a box or a resealable bag they came in a vacuum sealed bag so once its open they fall out everywhere if you keep knocking it over like I have lol. so just put them in a box or something I have 5 in my work bag all the time and replace as needed. I have never had one break.

Smooth even flow of ink for a satisfying feel and a nice written page. Unfortunately, the packaging is a non-resealable plastic bag rather than a box.

Vacuum sealed for shipping. Good black and easy use.

So the first set of cartridges arrived with a burst capsule that had ink smeared over the inside of the package. The second arrived in perfect condition and were an instant fit for my foundation pen. The ink lasts a fair amount of time. Not nearly as long as expected but probably about right for the price. Overall, the flow of the writing is okay with intervals of great vs limited flow but may also be in part due to the quality of my pen. I will use these until the quantity is depleted but afterward will upgrade both my pen and accompanying ink.

Fit my fountain pen perfectly.

These are the refill size for the Taylor Swift TTPD Fountain pen in case anyone is wondering.

Ordered a cheap pen from the same brand to give it a try and it ruined my ledger book. Horrible product, don't know if the pen or the cartridges are defective, or maybe both? Will be returning.