Up for auction here: an Antique Optimus Campingo/Optimill Stove Regulating Roarer Burner. It needs a good cleaning, a new jet (included), and new packing, but is functional as you can see from the pics. My It will fit only the antique Optimill stoves, their unnamed predecessor, and the sequent Campingo stoves, both the one and two burner models. It may fit other stoves using corse burner threads—I don’t know. Please note that on the Campingo stoves there are three different burner knob styles, and that this knob is neither of those found on the Optimill or it’s predecessor; you would have to improvise. This particular burner is off a 1938 model Campingo. The threads, and valve stem length, are wrong for all other stoves other than the three mentioned here.