It has an Alton, so 12V no problem. In my "some day I'm going to use that" drawer, I have a similar digital voltmeter and a couple of O2 sensors. Never could get used to calling them lambda sensors. Perhaps from working with the Japanese? Easier to pronounce O2 I suppose. I just need to buy a bung. Not sure why I didn't add one to the list when I placed my order at http://www.bungking.com/o2-sensor-bung/ I saw them on there.....bought a bunch of alloy fittings for the oil & fuel tanks (thanks to Oldhaven for the link).