for charge,and transfer data,Type C Extension cable with on / off for your convenience,need to use your own USB to Type C cable. No need to pull the cable to restart or reboots your devices, just press button to turn on and off.Help prevent the USB connectors from wear and tear due to frequent pulling and inserting the usb cable. USB C Type C USB for Power Switches for 4 Model B. Suitable for smartphones or tablet PC powerbanks and more Type C port devices.Not only can be used for your, but also for any Type C devices just like cellphone or tablets. Application: USB power output, LED light bar, USB small desk lamp / fan, LED small table lamp and other computer small power electrical power supply.