Model: Movie Meter
Cell type: Selenium
Measure type: averaging
Original price: $7
Walz began as the export arm of Okada Optical in Japan, but eventually became simply Walz (at least in the US). They made a few cameras, but I mostly know them for their accessories: namely filters and the odd light meter or two. It was Walz that ended up with the Norwood Super Director.
This is almost identical to their Direct F-Stop Meter. They made a raft of these things with small changes and lots of different names. (If you look for the manual, I've linked to the EV-LV: the same thing, different color).
I think it's a tad smaller than the Direct F-Stop (I can't easily find the other one to compare it right now). They both work the same way.
How to use it: there's a horizontal row of ƒ/stops that the needle crosses as you aim your meter. That's it. You turn the knob to tell it which film type/speed you're using. Because it's a movie meter, it assumes you're shooting at 16fps and the shutter speed will be around 1/25th or so.
I'm not a fan of these things, but I bought a box of meters and this was included.