Corn Electronics GK21S Brown Switch Gaming Keyboard

Compact 21-key kit with Brown switches

The Corn Electronics GK21S is a numpad-sized mechanical keyboard kit that uses tactile Brown switches for a balanced feel. It is aimed at enthusiasts who want a small programmable keypad for macros, media control or data entry without committing to a full-size board. The hot-swappable Kailh sockets let you change switches without soldering, and the 32-bit MCU with 8 MB flash stores up to three custom layers. Bluetooth 5.1 and a USB Type-C cable give dual-mode connectivity for desktop or mobile use.

Check switch preference and stabiliser fit

The Brown switches provide a tactile bump without an audible click, so confirm that suits your typing style before ordering. The PCB supports plate-mount stabilisers only; if you plan to use a different mounting style you will need compatible parts. The board accepts three-pin and five-pin MX-style switches from Cherry, BOX, Gateron and similar brands, but optical or proprietary stems will not fit. No keycaps or case are included, so you must supply those separately.

RGB lighting and macro layers expand utility

The anti-RGB LED placement uses a 256×256×256 driver capable of 16.8 million colours, enabling per-key lighting effects and music-reactive modes. On-board macro programming with three definable layers lets you assign complex shortcuts or media commands without extra software. A 750 mAh lithium battery powers the Bluetooth mode, while the USB Type-C connection charges the cell and provides a wired fallback. These features turn the bare PCB into a versatile control surface once you add caps and a case.