> For the complete documentation index, see [llms.txt](https://emotiv.gitbook.io/flex-2.0-user-manual/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/flex-2.0-user-manual/getting-started/flex-controller.md).

# FLEX Controller

![](https://lh7-us.googleusercontent.com/78no0oMsYkmwsdnzX-u3EruzpETsoibLfXfYyAfhT3V-ykaIPE_6TsL6Y-aAUqLIE27GbKcY-ly5_DXf3qqYrMdOqtn8aPMEumTTToccgh7iZu9Jlwa05nHxQa9tSpAhmc47ClvOknTFtIHDA49fPKY)

FLEX has 16 channels on the left + CMS\* input and 16 channels on the right + DRL\*\* output. The channels are positioned in two rows: rows A-H and J-Q, with an empty position above the CMS/DRL. 

\*CMS = common mode signal   \*\*DRL = driven right leg

\
FLEX also includes:

* **Power Switch.** The power switch is located next to the USB connector on the bottom edge of the unit. Move it to the right to turn it on and left to turn it off.
* **Power Indicator.** The power LED located below the logo indicates power on or off.
* **Charge Status.** The charge LED, located next to the USB-C connector, shows you the current battery status of the Flex Controller. 

![](https://lh7-us.googleusercontent.com/1Axw4s74kb9cOjcqOYB1F2IrvpQdVvz93gIX7BSSG7DrFVqAIsREQsnYQNns6aW1C87L1pG3MbUCK28EPpe6SsloDbY81qzzuhCx359f4u8Ss2LZMAod-bfoUdu5eLzt0rCr0ashNq2FHZhKGSiq36Q)