During a recent trip to Berlin, I happened to stay near the excellent Papeterie Moranga (just off Winterfeldtplatz), and came across two beautiful pens from Taiwan that I'd never seen in the wild before. One was the Bronze Age eyedropper/converter (which I purchased) and another was the more recent version, Gold Armour, which another FPner writes a wonderful review of here. If you are in the US, I believe there are one or two online stores that carry these pens, but they are (so far) relatively difficult to track down. These pens are so great, though, that I imagine they will become much more visible in the next few years. To my eye, they are as interesting, if not more, than the Opus eyedroppers. Highly recommended!
The pens are a striking combination of brass and transparent acrylic (at least I am assuming it's acrylic), which can double as both an eyedropper and converter. I was torn between them, but ultimately went with the faceted edges of the Bronze Age. (The Gold Armour version features a round cap that has small points to prevent it from rolling, and can also come with a beautiful bronze colored nib.)
I have no connection to Moranga or Fine Writing International--just a happy pen-owner! And if you are in Berlin, Moranga also has a lot of other wonderful stationary items--including new Midori notepads that I haven't yet found for sale in the US. The owner is also super friendly, and let me try out a ton of pens, including the newish line of Sailor Naginata Togi nibs.