Shown are 4, lower wattage mercury vapor lamps. The two A23 shaped Hg lamps are made by General Electric, one in clear and the other with the deluxe while phosphor coating. The other two, with E17 shaped bulbs, are 50 watt Hg lamps. One is by Iwasaki Electric (EYE), and the other is by an unknown company out of Romania. The arc tubes in the 50 watt lamps are very tiny. If anyone out there has a 50 watt Hg lamps ballast they want to part with, please let me know. I going to mount the ballast and lamp in an industrial vapor tight fixture and use it as a porch light. (e)