This is a Gotham Audio Decay meter for an EMT Plate Reverb. Gotham Audio out of NYC was the distributor for EMT products in the US. They also handled Telefunken, Neumann and Studer. This is a Gotham Decay meter for an EMT plate. I've had it for decades and now clearing more stuff out. Never seen another one like this. It's tested and works as it should. This one does not have the option of remote controlling the decay of the plate however.
The coolest thing about this meter, compared to the EMT, is that this one is zero hassle to install, it even has the original panel clips still with it. So, .090 or .125 aluminum panel that fits the space you have in your console, cut a rectangle in it. Any machine shop can do this in five minutes if you're not at ease with it. Powder coat, pop in the meter....two wires. Done.
More clearing out coming with what is most likely the largest set of original, stereo Painton faders on the planet. Inquire.