Schreibgerate standard ink converter │ cartridge converter made of synthetic material │ fits standard fountain pens and rollerball pens │ refillable,Black

a) it states it is suitable for all standard fountain pens. It is not, it didn't fit my montblanc, which takes standard ISO international cartridges. It is not accurately described.b) even worse the Amazon returns system doesn't apply - you have to post it back yourself, to Germany! And they will only refund the cost if they agree it is their fault. So it's not worth the risk of returning it at my own cost to a european address, it would cost more than the item.In the end Amazon refunded it themselves, great customer service from them as always, but beware of the above when considering purchase.

Coming up to Christmas and card writing time, I bought a calligraphy pen set last year. Came to use it this year and the single use cartridges had dried out. I have bottles of inks and tried to refill them ended up with inky fingers and sink! Found these on Amazon ordered three. Perfect fit and now it only takes a minute or two and they are refilled with whatever colour ink I choose, The calligraphy set is Mont Marte not sure if these will replace every cartridge type. I think pens like Parker, Sheaffer and Cross have their own adapters. These seem to fit the standard refills.

I have searched for a long time and finally find a converter for MUJI fountain pen. That's it!

Purchased this as it came up for sale when I searched on “cross pen ink converter”. It isn’t compatible with my Cross fountain pen. Fortunately, it does fit my Parker fountain pen so I’m using it in there. Basic principle of sucking ink up into a cartridge. When pushing it into pen, no sense of it connecting like you would with a cartridge so just made an assumption that when I put the pen together it wouldn’t leak. So far so good.

Bought the wrong size by mistake (needed the thinner one) but the cost and hassle of posting back not work the bother.