Weston Meter!

Those were the days, long since gone..when anyone using one of these was a REAL photographer.
I saved up pennies in my youth to get one of these beauties. The exposure was guaranteed correct if you measured the light falling on the subject, and having set the film speed, rotated the dial to cover your aperture setting, the readout then was transferred to the camera and bingo....a correct exposure every time. They belong in a museum today, with metering built into each camera of any real significance!!
The beauty too was it used no batteries either. A Selenium cell picked up the light for you! This one is in full working order today and it's one of the early models too!