The 21XX is a modern keyboard inspired by classic designs, particularly the Cherry 2XXX series and IBM Unsaver keyboards. It features a unique build with a 5.5° typing angle and a 25.5° angle for the function row, using high-quality 6063 aluminum for the case and a 5052 aluminum plate for the F-row cluster. The keyboard is designed for a weight of approximately 3900g unbuilt and 4300g built.

The PCB, designed by Cipulot, is compatible with QMK and VIAL, and includes features like indicator lights and 5V solenoid support. It utilizes a solder-only assembly and has a faux integrated cable with an internal USB-C port, enhancing its vintage aesthetic. The layout supports a plateless top-mounted assembly for the main typing area, while the F-row has a separate top-mounted PCB for optimal functionality. The design emphasizes chunky bezels, rounded corners, and a classic Cherry lip, making it a stylish choice for keyboard enthusiasts.