I've been keeping freshwater fish for a few years and picked up a spare light a while back, but I've got no idea what to do with it. And haven't found information online about it, I assume it's just a bit old.
I figured it was for a salt water tank, and this is the only salt water site I'm familiar with, any help would be apprieciated.
I haven't found a model number so here's a photo (or two).
I'm used to simple one bulb lights

.