Ergonomic mechanical split keyboard with replaceable key caps. The key switches are not replaceable. Has red (linear) keyswitches. The keyboard uses layers to get to additional keys. The key mapping is fully programmable using QMK. This has a usb-c port to connect to a computer, and the two halves connect to each other using a 4-pin audio cable, so you can use a longer cable if you want to separate them further.
This is somewhat similar to the Kinesis Advantage 360 in that it's split and moves a bunch of the special keys to the thumbs to reduce pinky strain.
This is the Redox keyboard on github that I built myself.