Manufactured in from the late 1940s to the early 1950s by General Electric. This is a fairly classic and inexpensive meter. It’s not real sensitive and has to be used mostly outdoors as it generates it’s power from the metering solar cell. By removing the top cover it's possible to get an acceptable reflective estimate (it would be necessary to come up with a conversion table as the meter wasn't intended to be used that way). It has two sensitivity ranges plus an incident mode. The two ranges are controlled by a little door over the top of the meter--if it's open then it's in the more sensitive mode.

Still working but I have no way to verify its accuracy.