With the Thunderbolt  3 (USB-C) to Thunderbolt  2 adapters you can use Thunderbolt and Thunderbolt  2 devices  - for example external hard drives or Thunderbolt docks  - with any Thunderbolt  3 (USB-C)  / USB  4 Connect the port on your Mac.
 Since it is a bidirectional adapter, you can also use it to use new Thunderbolt  3 devices with a Mac with Thunderbolt or Thunderbolt  2 connection and macOS  Join Sierra or newer.
 You can also use it to display Thunderbolt-enabled displays such as the Apple Thunderbolt Display and LG  Thunderbolt  2 displays with each Thunderbolt  3 (USB-C)  / USB  4 Connect the port on your Mac. For the Apple Thunderbolt Display you then need a power source because it does not support the transmission of electricity through the adapter.
 Note: This adapter does not support DisplayPort displays such as the Apple LED Cinema Display or DisplayPort and Mini DisplayPort displays from other manufacturers. You can find more information on the Apple Support page  for the Thunderbolt 3 (USB-C) to Thunderbolt 2 adapter.