Mine takes 2 or 3 9-volt batteries. Came from England. I was working on nuclear imaging cameras over there, we moved the operation here, and all the tooling and equipment got boxed up and sent over. This one wasn't type-certified in the US, so it had to be made to go away. I took care of that aspect of it.
A year ago or so I did a survey of household items and their radiation levels, it was kinda surprising. Ah, here it is: (thanks google) Radiation survey of everyday objects:
Background radiation, 4 sites inside house: 1.5 Counts per Second (CPS) Background radiation, 4 sites outside house: 1.5 CPS
4 over-ripe bananas, sensor in contact with skin: 3 CPS Clean diapers: 1.5 CPS (no detectable radiation; same as background) Dirty diapers, measured at top of diaper pail: 2 CPS (suspect banana involvement) 6 month old kid: 1.5 CPS plus drool and two giggles "First Alert" smoke detector, with Americium goodness: 50 CPS on surface 10 year old Trijicon (Tritium) gunsights on Glock 19: 1.5 CPS Granite boulder, roughly 1 meter in diameter. Pink: 4 CPS Black: 3 CPS Blue/black boulder of unknown ignious type: 1.5 CPS Garden soil: 1.5 CPSObviously this is only a slightly scientific survey, but shows some interesting non-background results.