My great uncle's light meter!  I used it as a kid, back in the 70s.  bearing in mind that film speed from pre-war didn't go anything like modern 100ASA+ the max seen is 64 (but the lettering for 64 is long faded) In theory, you can just move the gauge around the right number of spaces to a guestimate of modern film speeds.  

I believe these need a few minutes of sunlight to charge up some form of cell inside, before they work.  First time out of the case in 45 year, having set the zero fine trim, the needle didn't respond, but after a few minutes, it appears to  be working fine.

That said - PLEASE treat this as a vintage museum piece, and don't be buying it as a modern highly calibrated light meter - I cannot vouch that the readings it gives are accurate. It is almost 90 years old, after all!

Comes complete with it's original neck strap and leather case.

Thanks for looking