Alternatively, you can build an Adafruit MacroPad in 15 minutes. It's the same concept with a custom keyboard, an OLED, and a rotary encoder. I've been using it for years, and not only is it compatible with Linux, but the code is also available and is 100% customizable.

Site is hugged to death, but looks like the XPPen ACK05 product mentioned in title is a Bluetooth shortcut pad that looks like a number pad with an iPod wheel, intended for artists to quickly undo/redo, switch tools, and zoom/rotate canvas.

For those who don't RTFA and just see the headline: "Floss" as in FLOSS (Free Libre Open Source Software), not Floss as in the teeth-cleaning instrument.

Titles are hard but something like "The XpPen ACK05 remote on Linux using only FLOSS" would be less wordy