Corn Electronics GK21S Gaming Keyboard Red Switch 750mAh

Compact Custom Mechanical Kit

The Corn Electronics GK21S is a numpad-sized mechanical keyboard kit aimed at enthusiasts who want to assemble a compact custom board. It ships with a 32 bit MCU and 8M flash for onboard firmware storage, plus a hot-pluggable Kailh connector so switches can be changed without soldering. Red linear switches are included and the PCB supports plate-mount stabilisers for a stable typing feel. Bluetooth 5.1 and a Type-C USB cable provide dual-mode connectivity for desktop or mobile use.

Check Compatibility Before Ordering

Verify that your operating system recognises standard HID keyboards over Bluetooth 5.1 or USB so the board works without extra drivers. The PCB accepts three-pin or five-pin MX-style switches including Cherry, BOX and Gateron types, so confirm your preferred switches match that footprint. Because the kit requires switch installation, ensure you have a switch puller and a clean workspace. The 750mAh battery charges over Type-C, so a USB power source is needed for wireless use.

Bundled Extras Expand Functionality

The 16.8 million colour per-key RGB array is driven by three 256-channel LED drivers and supports music rhythm and sound-reactive lighting effects. Onboard macro programming lets you define three custom layers directly on the device, useful for gaming shortcuts or productivity macros. Anti-RGB lamp positioning improves shine-through on compatible keycaps. No keycaps or stabilisers are included, so those must be sourced separately to complete the build.