Use the Thunderbolt port of this adapter to connect your Mac to a display that uses a Thunderbolt or Thunderbolt 2 cable. For example, you can use this adapter to connect your Mac to an Apple Thunderbolt Display or LG Thunderbolt 2 display.
Data transfer
Thunderbolt or Thunderbolt 2
You can also use the Thunderbolt port of this adapter to connect an external hard drive, dock, Mac, or other device that uses a Thunderbolt or Thunderbolt 2 cable for data transfer. This adapter supports data-transfer speeds up to 10Gbps with Thunderbolt devices, and up to 20Gbps with Thunderbolt 2 devices.
This adapter is bidirectional, which means you can use it to connect Thunderbolt 3 devices to a Mac that has a Thunderbolt or Thunderbolt 2 port. In that case, the Mac must be using macOS Sierra or later, and the device using Thunderbolt 3 must provide its own power.