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Black mechanical keyboard kit with brown switches and RGB backlighting

Corn Electronics

Corn Electronics GK21S Brown Switch Gaming Keyboard

SKU CH-99HJ-H9DDD

A compact 21-key mechanical numpad kit with hot-swappable Brown switches, Bluetooth 5.1 and USB-C dual connectivity, 16.8 million-colour RGB lighting, macro programming and a 750 mAh battery

  • Key SwitchBrown Switch
  • Keyboard ColorBlack

Key Switch Type Brown Switch

Keyboard Color Black

  • Hot-pluggable Kailh connector lets you swap switches without soldering
  • Bluetooth 5.1 plus Type-C cable gives dual-mode connectivity
  • 32-bit MCU with 8M flash enables three custom macro layers
  • 8 million colour RGB with music rhythm and sound control
  • 750mAh battery powers wireless sessions

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.

Highlights

  • Hot-pluggable Kailh connector lets you swap switches without soldering
  • Bluetooth 5.1 plus Type-C cable gives dual-mode connectivity
  • 32-bit MCU with 8M flash enables three custom macro layers
  • 8 million colour RGB with music rhythm and sound control
  • 750mAh battery powers wireless sessions

Specifications

Key SwitchBrown Switch
Keyboard ColorBlack

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Questions about this item

Does the GK21S kit include keycaps and switches or must they be purchased separately?

The GK21S is a PCB kit with hot-pluggable Kailh connectors and plate-mount stabilisers; keycaps and MX-compatible switches such as Cherry or Gateron are not included and must be bought separately.

Which switch type is already selected for this GK21S listing?

This listing is configured with Brown tactile switches; the PCB accepts three-pin or five-pin MX-style switches if you wish to swap them later.

How long can the 750 mAh battery run the keyboard over Bluetooth 5.1 with RGB lighting active?

Battery life varies with brightness and effects; the 16.8 million colour RGB and 32-bit MCU draw more power, so expect shorter run-time than with lighting off.

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