If you know what these are, you probably have an MP-2 preamp like mine. These came with mine in 1995 (I'm old) and they have served me well, but I never plug them in anymore. Somebody who never had a "Pedal Pack" from ADA back in the day might like them.
They work fine, see the attached videos for a demo of me using every button - the patch numbers are changing on all the gear in the rack. The Quad switch accesses 4 CC commands, which are taped to the bottom of the switch for your/my convenience. There's a video of me doing a demo of it switching effects on/off in the orange Boss GX700 in the rack. It's main purpose is to switch stuff in the MP-2, but it'll work with any MIDI device.
You can get the whole manual at the ADA Depot (adadepot.com) to figure out how.
Comes with the MXC pedal, Quad Switch and CC Pedal (expression/wah etc.) and a few extra buttons. You're gonna need them, I have replaced all of them (I'm sure) by now. They're plastic, they dry out, get brittle and break when you stand on them....it happens. You will get good at replacing them :) Also includes original ADA power supply and a 7-pin MIDI cable to run phantom power to the pedals, if you wish....othewise, you have to put the wall wart on your pedalboard.
It was covered with low tack painter's tape to protect the surface while I gigged for 20 some years with it - This resulted in a big ol mess that I did my best to clean up for you. You can put more tape on if you like, I don't recommend it. (there are before/after pix showing the tape)
Video of MXC pedal demo: https://youtu.be/dkAX-3O0NYs?si=y74do0Qzeyp8-GHk
Video of Quad Switch demo: https://youtu.be/RzrLVwk2MUk?si=wx3pXga8g4BvoWoU