Appears to be the same plate and circuit as Egnater had on some of their cabinets. Same TM 412B v1.0 as the one pictured here. Mine also says 16 June 2007.

My Vengeance 412a cabinet came with an open, no load, to the 16 ohm input from the factory with this same plate arrangement. Thanks Egnater. Had the cabinet sitting for years before I decided to hook to a head. At first thought the my TopHat had died. Tried it with an Egnater Renegade head and blew both fuses. Definitely check to see that your speaker cable is seeing a load low impedance load before connecting a cabinet equipped with these switching circuits to a tube head. An open circuit, as in no speaker load, could blow your fuse, tubes, or a transformer.

BTW calling Egnater will not get you a replacement. The company is now "Boutique Amps Distribution", they have all but abandoned the Egnater line. I'll either have to by the Plug and Play or ditch the stereo mono switching circuit.

bought for a behringer 4-12 stereo Cab that had a bab main input jack..
the size was a bit different..
but i made it work..
ideally will have to replace again with one that fits
but works awesome. the leads were a bit short.

I had installed one of these a couple of years ago to use a 4x12 Marshall cabinet with an Axe-Fx II and a Duncan PowerStage 700, so I wanted the cabinet to be wired in stereo. The 2 stereo 8 ohm inputs have worked great so far. This past week, I was testing out some new pedals with an old Marshall head into the 16 ohm input. At first I thought something was wrong with the head, but after troubleshooting cables and everything else, I realized the 16 ohm input was dead. I'm pretty good with electronics, so I looked at the schematic and the Plug and Play uses stereo jacks with the equivalent of DPST switches in them to reroute the signal depending on which jacks are being used. I used an ohmmeter to confirm my suspicions about the 16 ohm jack being dead. I pulled the plate off the cabinet and manipulated the metal "switch" prongs inside the jacks with a very small screwdriver. Note: the problem was actually with one of the other jacks where the switching occurs, not the 16 ohm jack. I sprayed some DeOxit into the back of the jacks, so between moving the prong with a small screwdriver and spraying it out, I got it to work again. Hopefully this helps someone Googling this. You can always try repeatedly plugging and unplugging the jacks several times to get it to reset (didn't work for me). I think by leaving my rig setup with the 2 - 8 ohm inputs always plugged in has fatigued the metal switch prong inside the plugs, so maybe leaving these jacks plugged in while not in use is not a good idea? The big take away: should we really trust our precious amp heads to some tiny metal prong switch inside a jack that can easily fail?

Not sure how to rate this. For years, I've read other people's reviews of things online and seen 1 person out of a dozen post a story like "I ordered one and it was broken out of the box so I ordered a replacement and it was broken too" and thought to myself "yeah you probably set it up incorrectly or are doing it wrong." Well...I am now one of those people. I am fairly confident I have set this up correctly. It's a very straight forward install, but more importantly, I bought 2. One for each of my 4x12 cabs. One works perfectly. The other...nope. Tested w/ the DMM and the ohms are not correct: 8 ohms for the 4 ohm input and the 16 ohms input tested open. The right input tested correctly at 8 ohms. Swapped with the working one and it was same behavior.

I assumed I was at fault and did something wrong, damaged it or something so I ordered another one. Well unfortunately the new one seems to have the same defect. Very confusing. This is a really simple circuit, one that I probably could have wired up myself even with limited electrical knowledge but at this price, I figured "why bother." Can't quite figure out where the fault is.

Anyway, might want to buy two if you are on a time crunch and absolutely need one to be working. It's a great product and fills a specific need - mine being that my cabs are used as backline fairly frequently so they need to be able to work with any amp head someone brings.

Just got this today as a gift. I put it in a 2x12 cab with 2 4 ohm speakers. Impedance is 4L 4R 2mono and 8Mono.
It is a fantastic plate. Just follow the directions.

Excellent product and helped add some versatility to a 412 cab loaded with 16 ohm speakers. I run all 4 or the top and bottom two speakers separately. Easy to install, just make sure you have your wiring done properly and verify with load readings.

Changed my cab from mono to stereo with this plate. Very easy , looks great

Easy to convert a mono cab into a stereo/mono cab. Just plug in speakers and go!

Great product. Heavy metal construction. I built four separate 1x12 cabinets and installed one of these in two of the cabinets. This way I have the option of running a single 1x12, two of the cabinets in mono, two of the cabinets in stereo, or if I want to go all out, I can run all four cabinets in a 2x12 stereo setup.

If you're the tinkering type, this item is worth every penny. Got so tired of removing the back off of one of my cabs, every time I wanted to try a different wiring scenario, or A/B speakers in my 2x12. This works flawlessly. Worth every bit of the time for the jigsaw project to make a hole to fit it. Great item and a great price.