Exactly what it says on the tin, 8 programmable buttons hooked onto a Pico (BYO CE08494 & CE08554)

You'll also need to add RP2040 in Arduino IDE. Go to File > Preferences > Additional boards manager URLs and add in

https://github.com/earlephilhower/arduino-pico/releases/download/global/package_rp2040_index.json