Model: Electrophot 14-A
Designer: J Thos Rhamstine
Cell type: Selenium
Measure type: Reflecting/averaging
John Thomas Rhamstine is sometimes credited with inventing the first photo-electric meter back around 1932. Unfortunately it used a battery, was very heavy, and was not beloved by photographers. In Germany Phillip Gossen and in the USA Edward Weston both introduced smaller, lighter, battery-less photoelectrics and began an industry.
Rhamstine redesigned his meter so it didn't require a battery, but they never caught up. The big boys (Weston, GE, DeJur, and so on) had advertising and distribution on their side, but Rhamstine plugged along.
This one is a later model, perhaps the last —it shows up on a magazine meter survey from 1948. I believe the calculator dial is in Weston numbers, which were an unoffocial standard in the US until ASA took over. The regular Model 14 has a calculator dial calibrated for American Scheiner.
The most interesting part of this meter is its readout. It's a direct-read for film with speed 12 at 1/25th second, or you could bring the ƒ/stop into the calculator dial below and work out the shutter speed. The other noteworthy thing (for me anyway) is how active the needle is after all these years. A lot of meters from this era are dead or sluggish. This appears to be working and accurate.