> For the complete documentation index, see [llms.txt](https://emotiv.gitbook.io/emotivpro-v3/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://emotiv.gitbook.io/emotivpro-v3/event-markers/usb-markers.md).

# USB markers

To configure markers sent by a USB device:

1. Click on **Settings** which can be found at the top right-hand side of EmotivPRO. 
2. Click on **USB marking** from the menu on the left-hand side of the screen.
3. Go to the USB Device drop-down list and select the USB device you want to connect. 
4. If you don’t see the USB device you’re looking for in the drop-down list, click on **Refresh device list**. 
5. Once you’ve selected a USB device, click on **Start**. 

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Please note: 

* USB mouses and USB keyboards are not supported. 
* Marker values from a USB port are in the range of 0 to 127. 

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You will see a vertical pink line in the data stream in Raw EEG, Performance Metrics and Motion Sensors views when a marker has been added successfully and will be able to view the markers in the session timeline and exported data file.<br>