Rotring Fountain Pen Converter

Very nice and stylish converter. I use this converter on my Rotring Artpens, but it also fits my Tombow fountain pens as well. It's a nice touch to have a red line at the end of the piston, but I won't get this converter if it's not for my rotring pens. You can get the same quality pelikan converter for $2 less.
If you do get this converter, don't forget to pre-wash this converter before use. I notice a layer of oil inside the converter when I got it fresh from jetpens

This is the converter to get if you own those rare coveted Rotring 600 and 900 series fountain pens. Seals tight with section and no leaking. The red ring you see on the converter by the way, is part of the rubber stopper at the end of the piston; it is not a red ring printed on the plastic body, as Rotring typically has characterized on its pens.

Converter works perfectly with my Rotring Artpen. As mentioned below, you'll want to give it a rinse before using.
You do need to press rather firmly to get it to attach to the pen, once it does though, the seal is tight. I haven't had any leakage with it, and my Rotring is always getting hustled about in my purse!

Jetpens listed his on the Kaweco Special + Rotring Fountain Pen Converter. They do not work together. The converter keeps disengaging from the pen cause ink leakage.

What does it mean by converter? (New to Drawing and stuff like this)