That's right. They make lighting and gels for lighting. They do other stuff I think, too. They teamed up with the Strobist blog to create a pack of 55 gels for photographic flashes. So, it's the same.
They are thin, but at the low power I'm using they seem to be ok. They also do swatch books directly from them. I'll have to check out Lee filters and see what they offer! Thanks for the info.