Yeah, I've seen those. I don't know how good they are compared with the Philips and Osram ones, though.
They were used in laboratories as sources of specific lines of radiation, such as mercury, sodium, neon, argon and such like. If you can get the good ones, they are very collectable. I am hoping to get some more Philips ones soon
![Bulb Man :bulbman:](/Smileys/default/bulbmanicon.png)