Introduction
This manual provides detailed instructions for the Newmight USB C to Dual HDMI Adapter. This adapter is designed to connect your USB-C enabled device to two external HDMI displays, enhancing productivity and visual experience. It supports various display configurations and is compatible with a wide range of devices.
Key features include:
- Dual HDMI Connectivity: Connect two monitors simultaneously for extended or mirrored displays.
- High Resolution Support: Up to 4K@60Hz for single HDMI output and 4K@30Hz for dual HDMI output.
- Plug-and-Play: No drivers or software installation required.
- Efficient Heat Dissipation: Aluminum alloy housing for stable, long-term performance.
- Wide Compatibility: Works with most Type C laptops with Thunderbolt 3/4, including MacBook Pro, MacBook Air, iPad Pro, iPad Air, Dell XPS, HP Spectre x360, and iPhone 15/16 series.
Package Contents
- 1 x Newmight USB C to Dual HDMI Adapter
- 1 x User Manual
Setup
Follow these steps to set up your Newmight USB C to Dual HDMI Adapter:
- Verify Host Device Compatibility: Ensure your laptop or device has a USB-C port that supports video output (DisplayPort Alternate Mode or Thunderbolt 3/4). Ports that only support data transfer or charging are not compatible for video output.
- Connect HDMI Cables: Connect your HDMI displays to the HDMI ports on the Newmight adapter. Ensure you use HDMI 2.0 cables or better for 4K resolution support.
- Connect Adapter to Host Device: Plug the USB-C connector of the adapter into a compatible USB-C port on your laptop, tablet, or smartphone.
- Power On Displays: Ensure your external monitors are powered on and set to the correct HDMI input source.
- Automatic Detection: The adapter is plug-and-play, so your operating system should automatically detect the connected displays.

Image: Illustration of compatible USB-C port types (Thunderbolt Full Function, With DP Alt Mode, Data Transfer + DP Alt Mode) and incompatible types (Data Transfer Only, Charging Only).

Image: The Newmight USB C to Dual HDMI Adapter shown with its USB-C connector and two HDMI ports, ready for connection.
Video: An overview of the Newmight USB C to Dual HDMI Adapter, demonstrating its features and connectivity.
Operating Instructions
Once connected, you can configure your display settings through your operating system.
Windows Operating System
For Windows devices, the adapter supports Mirror Mode, Extend Mode (SST), and Extend Mode (MST) for dual monitors.
- Mirror Mode (A-A-A): All displays show the same content.
- Extend Mode (SST - A-B-B): The primary display (laptop) shows one content, and both external monitors mirror each other, showing a different extended content.
- Extend Mode (MST - A-B-C): The primary display (laptop) shows one content, and each external monitor displays unique, extended content.

Image: Visual representation of display configurations for Windows, including Mirror Mode (A-A-A), Extend Mode (SST, A-B-B), and Extend Mode (MST, A-B-C).
macOS Operating System
Due to macOS limitations, when connecting two monitors, both external monitors can only display the same content (A-B-B or A-A-A). MST mode (A-B-C) is not supported.
- Mirror Mode (A-A-A): All displays show the same content.
- Extend Mode (A-B-B): The primary display (MacBook) shows one content, and both external monitors mirror each other, showing a different extended content.

Image: Visual representation of display configurations for macOS, including Mirror Mode (A-A-A) and Extend Mode (A-B-B). Note on macOS MST limitation is included.
Resolution Support
- Single HDMI Port: Supports up to 4K@60Hz.
- Dual HDMI Ports: Supports up to 4K@30Hz for each monitor.
Note: For 4K resolution, ensure your devices and HDMI cables (HDMI 2.0 or better) support 4K.

Image: A laptop connected to two external monitors via the Newmight adapter, demonstrating dual 4K@30Hz display capabilities.
Maintenance
To ensure the longevity and optimal performance of your Newmight USB C to Dual HDMI Adapter, follow these maintenance guidelines:
- Cleaning: Use a soft, dry cloth to clean the adapter. Avoid liquid cleaners or abrasive materials.
- Storage: Store the adapter in a cool, dry place when not in use. Avoid extreme temperatures.
- Handling: Handle the adapter and its cables with care. Avoid bending or twisting the cable excessively.
- Heat Dissipation: The aluminum alloy housing is designed for superior heat dissipation. Ensure the adapter is placed in an area with adequate airflow to prevent overheating during extended use.
Troubleshooting
If you encounter issues with your Newmight USB C to Dual HDMI Adapter, refer to the following common solutions:
- No Display on Monitor:
- Ensure your host device's USB-C port supports video output.
- Check that HDMI cables are securely connected to both the adapter and the monitors.
- Verify that monitors are powered on and set to the correct HDMI input.
- Try restarting your host device.
- Incorrect Resolution or Flickering Screen:
- Ensure your HDMI cables are HDMI 2.0 or better, especially for 4K resolution.
- Check your display settings on your host device and adjust the resolution and refresh rate.
- Update your graphics drivers on your host device.
- macOS Dual Monitor Limitation:
- As noted, macOS does not support MST (Multi-Stream Transport) mode for dual extended displays. Both external monitors will mirror each other (A-B-B) or mirror the primary display (A-A-A). This is a system limitation, not a product defect.
- Adapter Overheating:
- Ensure the adapter is in an open area with good ventilation. Avoid covering it or placing it in confined spaces.
- If the issue persists, disconnect the adapter and contact customer support.
Specifications
| Feature | Detail |
|---|---|
| Model | C21 |
| Product Dimensions | 5.12 x 1.34 x 0.55 inches |
| Item Weight | 1.76 ounces |
| Hardware Interface | HDMI, USB Type C |
| Special Features | Heat Resistant, Lightweight, Plug and Play, Portable |
| Compatible Devices | Laptops, Monitors, Projectors (with compatible USB-C port) |
| Single HDMI Output | Up to 4K@60Hz |
| Dual HDMI Output | Up to 4K@30Hz |
Warranty and Support
The Newmight USB C to Dual HDMI Adapter comes with a one-year warranty, ensuring product quality and a worry-free experience.
If you encounter any issues or have questions, our customer support team is available 24/7 to assist you and resolve any concerns. Please refer to the contact information provided with your product packaging or visit the official Newmight website for support.




