My son bought this flash hot shoe mountable vintage light meter a few days ago at a thrift store. It looks to be in good condition on the outside but the cover to the battery compartment is covered corrosion - I'm sure it can be cleaned. It takes a #625 button cell type battery which I should be able to find at RadioShack. If I can get it working, and it proves to be somewhat accurate, then I might be able to use it. At least one of my vintage 35mm cameras has a busted light meter. Other than a serial number listed on the bottom of the light meter, it has no brand name or manufacturing lable - I don't know who made it.