1. Introduction
Thank you for choosing the MOFII SK-645BTW Wireless Mechanical Keyboard. This manual provides essential information for setting up, operating, and maintaining your new keyboard. Please read it thoroughly before use to ensure optimal performance and longevity of your device.

Image: Top view of the MOFII SK-645BTW Wireless Mechanical Keyboard, showcasing its colorful round keycaps and compact layout.
2. Package Contents
Please check the package for the following items:
- MOFII SK-645BTW Wireless Mechanical Keyboard
- USB-A Cable (for wired connection and charging)
- User Manual (this document)
- Wireless Receiver (if applicable, for 2.4GHz mode)
3. Setup
3.1 Battery Installation
The keyboard requires 2 batteries for wireless operation. Locate the battery compartment on the underside of the keyboard. Open the cover, insert the batteries according to the polarity indicators (+/-), and close the cover securely.
3.2 Connecting the Keyboard
The MOFII SK-645BTW keyboard supports both Bluetooth wireless and USB-A wired connections.
3.2.1 Bluetooth Connection
- Ensure the keyboard is powered on and in Bluetooth mode (refer to the Operating Instructions for mode switching).
- On your device (laptop, tablet, etc.), enable Bluetooth and search for new devices.
- Select "MOFII SK-645BTW" from the list of available devices.
- Follow any on-screen prompts to complete the pairing process.
3.2.2 Wired (USB-A) Connection
- Connect one end of the provided USB-A cable to the keyboard's USB port.
- Connect the other end of the USB-A cable to an available USB port on your computer.
- The keyboard should be automatically recognized and ready for use.
4. Operating Instructions
4.1 Power On/Off
Locate the power switch on the keyboard, typically on the side or underside. Slide it to the "ON" position to power on the keyboard and to "OFF" to power it down when not in use.
4.2 Mode Switching
The keyboard supports multiple connection modes. Use the designated key combination or switch to toggle between Bluetooth and wired modes. Refer to the keyboard's markings for specific key combinations, often involving the Fn key.

Image: Close-up of the left side of the keyboard, showing keys like 'Tab', 'Caps', 'Shift', 'Ctrl', 'Cmd', and 'Alt' with their unique color scheme.
4.3 Function Keys (Fn Combinations)
The keyboard features various function keys that can be accessed by pressing the Fn key in combination with other keys. These typically include multimedia controls, volume adjustments, and system shortcuts.
- Fn + F1-F12: Access multimedia functions (e.g., play/pause, stop, previous/next track, volume up/down, mute).
- Fn + Other Keys: Specific system functions or shortcuts as indicated by icons on the keycaps.

Image: Close-up of the right side of the keyboard, highlighting keys like 'Back', 'Delete', 'Enter', 'Shift', 'PgUp', 'PgDn', 'Home', and 'End' with their distinct colors.
4.4 Ergonomics
The keyboard is designed with an ergonomic feature to provide a comfortable typing experience. Position the keyboard to maintain a natural wrist posture.

Image: Side view of the MOFII SK-645BTW keyboard, showing its profile and a hand positioned for typing, illustrating its ergonomic design.
5. Maintenance
5.1 Cleaning
To clean your keyboard, power it off and disconnect it from your device. Use a soft, lint-free cloth slightly dampened with water or a mild cleaning solution. Avoid excessive moisture and harsh chemicals. For dust between keycaps, use compressed air.
5.2 Storage
When not in use for extended periods, store the keyboard in a dry, cool place away from direct sunlight and extreme temperatures. Remove batteries if storing for a very long time to prevent leakage.
6. Troubleshooting
If you encounter issues with your MOFII SK-645BTW keyboard, please refer to the following common solutions:
- Keyboard not responding:
Check if the keyboard is powered on. Ensure batteries are correctly installed and have sufficient charge. For Bluetooth, verify it's paired correctly. For wired, check the USB cable connection. Try restarting your computer. - Bluetooth connection issues:
Ensure Bluetooth is enabled on your device and the keyboard is in pairing mode. Remove the keyboard from your device's Bluetooth list and attempt to re-pair. Move closer to your device to rule out interference. - Keys not working:
Clean the keyboard to remove any debris that might be obstructing the keys. If specific keys are not working, it might indicate a hardware issue. - Input lag or disconnections:
Ensure there are no strong wireless interference sources nearby. For Bluetooth, try connecting via USB-A to see if the issue persists.
7. Specifications
Key technical details for the MOFII SK-645BTW Wireless Mechanical Keyboard:
| Feature | Detail |
|---|---|
| Brand | MOFII |
| Model Number | SK-645BTW |
| Connectivity Technology | Bluetooth, USB-A (Wired) |
| Keyboard Description | Mechanical |
| Number of Keys | 84 |
| Switch Type | Mechanical |
| Keyboard Layout | QWERTY |
| Power Source | Battery Powered (2 batteries) |
| Material | Plastic |
| Compatible Devices | Laptop |
| Special Feature | Ergonomic |
| Color | Red |
| Country of Origin | China |
8. Safety Information
- Do not expose the keyboard to water or excessive moisture.
- Avoid dropping or subjecting the keyboard to strong impacts.
- Keep out of reach of children.
- Do not attempt to disassemble or modify the keyboard. This will void the warranty.
- Dispose of batteries according to local regulations.
9. Warranty and Support
MOFII products are designed for reliability and performance. For warranty information and technical support, please refer to the documentation provided at the time of purchase or visit the official MOFII website. Please retain your proof of purchase for warranty claims.