Introduction
Thank you for choosing the Keycool K21 MAX Wireless Mechanical Keyboard. This 21-key numeric keypad offers versatile connectivity options including Bluetooth, 2.4GHz wireless, and wired Type-C. Featuring hot-swappable mechanical switches, RGB backlighting, and durable PBT keycaps, it is designed for enhanced productivity and a customizable user experience across various operating systems.
Setup Guide
1. Unboxing and Initial Check
Carefully remove the keyboard from its packaging. Ensure all components, including the keyboard, USB receiver (if applicable), and Type-C cable, are present.
2. Charging the Keyboard
The keyboard is equipped with a 1500mAh battery. Connect the provided Type-C cable to the keyboard's charging port and a USB power source (e.g., computer, wall adapter) to charge. The indicator light will show charging status.
3. Connection Modes
The Keycool K21 MAX supports three connection modes: Bluetooth 5.0, 2.4GHz Wireless, and Wired (Type-C).
3.1. Bluetooth Connection (Fn + 1, 2, or 3)
- Locate the wireless switch on the side of the keyboard and slide it upwards to turn on the keyboard. The RGB backlight will illuminate.
- Press and hold the Fn key, then press the 1 key once to switch to Bluetooth mode 1. The 'W' indicator light will flash slowly.
- To enter pairing mode, press and hold the Fn key, then long-press the 1 key until the 'W' indicator light flashes rapidly.
- On your device (e.g., phone, computer), go to Bluetooth settings and search for "K21PRO 5.0" or similar. Select it to pair.
- Once connected, the 'W' indicator light will stop flashing.
- Repeat steps 2-5 for Bluetooth modes 2 (Fn + 2) and 3 (Fn + 3) to connect to up to three different Bluetooth devices.
*Note: The 'W' indicator light must be flashing rapidly for successful pairing.*
3.2. 2.4GHz Wireless Connection (Fn + 4)
- Locate the wireless switch on the side of the keyboard and slide it upwards to turn on the keyboard.
- Press and hold the Fn key, then press the 4 key once to switch to 2.4GHz wireless mode. The 'W' indicator light will flash slowly.
- To enter pairing mode, press and hold the Fn key, then long-press the 4 key until the 'W' indicator light flashes rapidly.
- Retrieve the USB receiver from its storage slot on the keyboard.
- Plug the USB receiver into an available USB port on your computer.
- The keyboard should automatically connect. The 'W' indicator light will stop flashing once connected.
*Note: The 'W' indicator light must be flashing rapidly for successful pairing.*
Video: Demonstrates Bluetooth, 2.4GHz, and Wired connection methods for the Keycool K21 MAX keyboard.
3.3. Wired Connection (Fn + 5)
- Connect the Type-C cable to the keyboard's port and the other end to your computer's USB port.
- Press and hold the Fn key, then press the 5 key once to switch to wired mode.
- The keyboard will be recognized by your computer and ready for use.
Operating Instructions
1. Key Functions and Layout
The Keycool K21 MAX features a 21-key numeric keypad layout. Keys are customizable, allowing users to personalize functions according to their needs.
2. Backlight Control
The keyboard features vibrant RGB backlighting with multiple effects.
- To toggle the backlight on/off: Press Fn + Back (the key with the 'X' icon).
- To switch between different backlight effects: Press Fn + 6 (the key with the 'gear' icon).
3. Hot-Swappable Switches
The hot-swappable PCB design allows you to freely replace the mechanical switches without soldering. This enables personalization of the keyboard's feel and sound to suit your preferences.
Image: Exploded view showing keycap, shaft body, top cover, PC positioning plate, Poron sandwich cotton, shaft pad, IXPE pad, PCB board, Poron bottom cotton, battery, and bottom cover.
4. PBT Keycaps
The keyboard is equipped with customized PBT keycaps, known for their durability, wear-resistance, and non-greasy texture, offering a comfortable and delicate feel.
5. USB Receiver Storage
A dedicated card slot is provided for storing the USB receiver when not in use, preventing loss and ensuring convenience.
Image: Close-up of the keyboard's side, highlighting the storage slot for the USB receiver.
Maintenance
1. Cleaning
- Use a soft, dry cloth to wipe down the keyboard surface regularly.
- For deeper cleaning, remove keycaps (using a keycap puller, not included) and use compressed air to clear debris from between switches.
- Wipe keycaps with a slightly damp cloth if necessary, ensuring they are completely dry before reattaching.
2. Battery Care
- Avoid fully discharging the battery frequently to prolong its lifespan.
- Charge the keyboard using the provided Type-C cable and a compatible power source.
- If storing the keyboard for an extended period, charge it to about 50% to prevent deep discharge.
Troubleshooting
1. Keyboard Not Connecting (Wireless/Bluetooth)
- Ensure the wireless switch on the side of the keyboard is turned ON.
- Verify the correct mode is selected (Bluetooth 1/2/3 or 2.4GHz) by pressing Fn + 1/2/3/4.
- For Bluetooth, ensure the 'W' indicator light is flashing rapidly (long-press Fn + 1/2/3) and your device's Bluetooth is enabled and searching.
- For 2.4GHz, ensure the 'W' indicator light is flashing rapidly (long-press Fn + 4) and the USB receiver is securely plugged into your device.
- Try restarting the keyboard and your device.
2. Backlight Not Working or Incorrect
- Ensure the backlight is turned on by pressing Fn + Back.
- Check if the battery is low; connect the keyboard to a charger.
- Cycle through different backlight effects by pressing Fn + 6.
3. Keys Not Responding
- Ensure the keyboard is properly connected in your chosen mode (wired, Bluetooth, or 2.4GHz).
- If in wireless mode, check battery level.
- If individual keys are not responding, check if the hot-swappable switch is properly seated or try replacing it.
- Test the keyboard on another device to rule out device-specific issues.
Specifications
| Feature | Detail |
|---|---|
| Brand Name | FEYA (also KEYCOOL) |
| Model | K21 MAX / K21 Pro |
| Number of Keys | 21 keys |
| Keycap Material | PBT keycaps |
| Operation Style | Mechanical |
| Switch Type | Sakura Breeze Switch (Hot-swappable) |
| Backlight | RGB |
| Interface Type | USB, Bluetooth / USB (Type-C) |
| Connectivity | Bluetooth Wireless (5.0), 2.4G Wireless, Wired (Type-C) |
| Battery Included | Yes |
| Battery Capacity | 1500mAh |
| Product Dimensions | ≈133mm × 90mm × 32mm (without keycaps) |
| Application | Desktop, Laptop, Number |
| Supported Systems | Windows, Mac, Android, iOS |
| Style | Standard, Ergonomics, Multimedia, Gaming, Mini, For Laptop, Numeric Keyboard, Multifunctional Keyboard |
| Origin | Mainland China |
Image: Diagram illustrating keyboard dimensions and key specifications.
Warranty and Support
Your Keycool K21 MAX keyboard comes with a standard return and refund policy. For detailed information regarding warranty coverage, returns, or technical support, please refer to the seller's policy or contact the seller directly.
Fast Delivery Guarantee
The product is covered by a fast delivery guarantee, which includes:
- A $1.00 coupon code if delivery is delayed.
- Refund if the package is lost.
- Refund if items are damaged.
- Refund if no delivery within 30 days.
Security & Privacy
Your personal details are protected and not shared with third parties without your consent. Payments are secure, and your privacy is maintained.
User Tips
- Experiment with different RGB lighting effects using Fn + Back and Fn + 6 to find your preferred aesthetic.
- Take advantage of the hot-swappable design to try different mechanical switches and customize your typing experience.
- Always store the 2.4GHz USB receiver in its dedicated slot on the keyboard to prevent misplacement.
- For optimal performance, ensure the keyboard is fully charged before extended wireless use.
- If experiencing input lag in wireless modes, try switching to wired mode for a direct connection.
