Marspark 6 Pieces Universal Fountain Pen Ink Converter International Fountain Pen Ink Cartridge Converter Refillable Standard Ink Plunger Converter (Red)

I have no complaints about these. I am surprised they have the LAMY logo on them and look authentic. I am not sure how they are getting away with that but they are. I have these in two of my LAMY pens and neither one has problems with leakage. These even have the little knobs on the side like the authentic ones do.

Not as good as the original that shipped with the pen

Very happy with those. I bought a set of fountain pens that all had dysfunctional converters, but when I switched to these, they worked perfectly. Super easy to use and no leaks. The size seems universal and fits my pens from different brands.

Got these for my lamy safaris and they worked pretty well with them.

You know, to me - and maybe I'm way out of line here, but to me - the word 'universal' is thrown around way too often. It's a very arrogant word. A universal remote. A universal watch strap. A universal fountain pen converter. I mean, not just 'global', which is pretty bold and daring in itself. But universal. That means to me that this object will fit any and every single fountain pen in the universe. Even the ridiculously oversized, square fountain pens used by the Vogon Constructor Fleet. Right? So imagine my surprise when I tried to put one of them in my Sheaffer fountain pen, which uses - get this - a standard, universal ink cartridge, and it didn't fit. I mean, come on. My Sheaffer was made right here on this planet. The same planet on which these converter cartridges were made. So out of the entire universe, this converter is supposed to fit every single pen in existence. But they couldn't even collaborate with one of the most wide-spread fountain pen companies on the same planet? Come on, guys. That's just lazy. There are no two points on this planet more than 12,000 miles apart. You went all over the universe, including places up to a billion light years away. Andromeda Galaxy? Sagittarius Cluster? You made those trips and worked with their manufacturers to make sure your converter fit their pens, but you couldn't stroll down the street to another Earthly company? Weak. So yeah, I guess it works fine for my Lamy pen. But not my others. I'm a little disappointed. Because I only have one Lamy pen, and I bought a six-pack of these converters. I guess I'll leave them to my children in my will, because I'll never get around to using any but the first one. So they will last at least for the rest of my life. Which, admittedly, is probably not more than about forty more years at best. But it just means more work. You know? Writing and printing out a little note to tuck into the box with the other five converters - "Dear [whomever has inherited these converters after Spacey's death], please enjoy these converters, but know that they only work with one pen in the universe, so far as I've been able to tell so far. And that pen already has one in it. So if you were lucky enough to inherit that pen as well, you may not even ever need these. You might want to go ahead and add these to your will." Well, heck. I just wrote it. I guess I'll copy and paste that into notepad and go ahead with the plan.