Introduction
The Docooler MK321BT is a versatile 3-key mini keypad designed for various applications, including gaming, office work, and multimedia control. It features a dual-mode connection (USB and Bluetooth 4.0) for flexible use and mechanical blue switches for a tactile and responsive experience. The keys are fully customizable to perform a wide range of functions, enhancing productivity and control.

Image: The Docooler MK321BT 3-Key Mini Keypad, available in black and white, showcasing its customizable functions such as Keyboard, Mouse, Multimedia, Character String, Game, and Macro Definition.
Package Contents
Please check the package for the following items:
- 1 x Docooler MK321BT Mini Keypad
- 1 x USB Type-C Data Cable
- 1 x User Manual (this document)
Product Overview
Familiarize yourself with the components and features of your mini keypad.

Image: A detailed breakdown of the keypad's features, including the front interface with power switch and USB Type-C port, a side Type-C interface, visible blue mechanical switches, and anti-slip foot pads on the bottom.
- Front Interface: Features a power switch (ON/OFF), a USB Type-C port for wired connection and charging, and a 'connect' button for Bluetooth pairing.
- Side Interface: An additional Type-C interface for convenient access.
- Blue Switch Buttons: Equipped with mechanical blue switches, providing a strong tactile feedback and crisp sound.
- Anti-slip Foot Pads: Located at the bottom of the keypad to ensure stability during use.
Setup
Wired Connection
- Connect the provided USB Type-C data cable to the front USB Type-C port on the keypad.
- Connect the other end of the USB cable to an available USB port on your computer.
- Ensure the power switch on the front interface is in the 'ON' position. The keypad will be recognized automatically by your system.
Wireless (Bluetooth) Connection
- Ensure the power switch on the front interface is in the 'ON' position.
- Press the 'connect' button on the front interface to activate Bluetooth pairing mode. The indicator light will flash.
- On your device (computer, tablet, mobile phone), open Bluetooth settings and search for new devices.
- Select 'MK321BT' (or similar name) from the list of available devices to pair.
- Once paired, the indicator light on the keypad will stop flashing, indicating a successful connection.

Image: The Docooler MK321BT Mini Keypad, illustrating its USB+BT4.0 dual-mode connection for easy switching between wired and wireless use.
System Compatibility
This keypad is compatible with various operating systems. Key definition setting software is provided for Windows systems.
- Windows: Fully compatible, including key customization software.
- Linux/Mac: If you use Linux or Mac, you need to set up the key definitions on a Windows system first. After configuration, the keypad can be plugged into your Linux or Mac device and used with the saved settings.

Image: Visual representation of the keypad's system compatibility across various devices including laptops, desktop computers, tablets, and mobile phones.
Operating Instructions
Key Customization
The keys on your Docooler MK321BT Mini Keypad can be customized to perform a variety of functions. Use the dedicated software (available for Windows) to assign functions such as:
- Keyboard functions (e.g., specific keys, shortcuts)
- Mouse functions (e.g., clicks, scroll)
- Multimedia functions (e.g., play/pause, volume control)
- Character string functions (e.g., inputting predefined text)
- Game functions (e.g., specific in-game actions)
- Macro definition functions (e.g., executing a sequence of commands)
Switching Connection Modes
The keypad supports both USB wired and Bluetooth wireless connections. You can easily switch between these modes as needed. When the USB cable is connected, the keypad operates in wired mode. When disconnected, it will attempt to connect via Bluetooth if previously paired.
Important Operating Note
Please note that the one-click open/start function cannot be used when the keypad is operating in wireless (Bluetooth) mode. This function is only available in wired mode.

Image: A close-up of a hand interacting with the keypad, emphasizing the comfortable ergonomic design of the buttons and the stated 50 million times button lifespan.
Maintenance
To ensure the longevity and optimal performance of your Docooler MK321BT Mini Keypad, follow these simple maintenance guidelines:
- Cleaning: Use a soft, dry cloth to wipe the surface of the keypad. For stubborn dirt, a slightly damp cloth can be used, but ensure no liquid enters the device. Do not use harsh chemicals or abrasive cleaners.
- Storage: Store the keypad in a cool, dry place away from direct sunlight and extreme temperatures.
- Handling: Avoid dropping the keypad or subjecting it to strong impacts, as this can damage the internal components or mechanical switches.
Troubleshooting
If you encounter issues with your mini keypad, refer to the following common problems and solutions:
- Keypad not responding:
- Ensure the power switch is in the 'ON' position.
- If using wired mode, check if the USB cable is securely connected to both the keypad and your computer. Try a different USB port.
- If using wireless mode, ensure the keypad is paired correctly via Bluetooth. Try re-pairing the device.
- Check the battery level if in wireless mode. Charge the keypad if the battery is low.
- Bluetooth connection issues:
- Ensure Bluetooth is enabled on your host device.
- Move the keypad closer to your device to rule out range issues.
- Remove the keypad from your device's Bluetooth list and attempt to pair again.
- Restart both the keypad (turn off and on) and your host device.
- Keys not performing assigned functions:
- Verify that the key customization software was used correctly and settings were saved.
- If using Linux/Mac, ensure the customization was performed on a Windows PC and saved to the keypad's onboard memory.
- Remember that the one-click open/start function is not available in wireless mode.
Specifications
Technical specifications for the Docooler MK321BT Mini Keypad:

Image: A table detailing the product parameters and a diagram illustrating the dimensions (length, width, height) of the Docooler MK321BT Mini Keypad.
| Specification | Detail |
|---|---|
| Type | Mini keyboard |
| Model | MK321BT |
| Key Number | 3 |
| Connection Mode | USB + Bluetooth 4.0 |
| Mechanical Switch | Blue switch |
| Interface Type | Type-C |
| Service Life | 50 million times |
| Battery Capacity | 140mAh |
| Working Voltage/Current | 5V@15mA |
| Item Size | 7.5 * 3.7 * 2.8 cm (2.95 * 1.46 * 1.1 in) |
| Item Weight | Approx. 29g (1.02 oz) |
Warranty and Support
For warranty information or technical support, please refer to the documentation provided at the time of purchase or contact Docooler customer service through their official website or the retailer where the product was purchased.