Apple Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter
Thunderbolt 3 to Thunderbolt 2 adapter
This adapter allows you to connect thunderbolt 2 peripherals to a thunderbolt 3 equipped computer, it is bi-directional so you can also connect thunerbolt 3 devices to your thunderbolt 2 machine. Please note this is not compatible with mini displayport items.
The Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter lets you connect Thunderbolt and Thunderbolt 2 devices — such as external hard drives and Thunderbolt docks — to any of the Thunderbolt 3 (USB-C) ports on your MacBook Pro or other thunderbolt 3 enabled workstations.
As a bidirectional adapter, it can also connect new Thunderbolt 3 devices to a Mac with a Thunderbolt or Thunderbolt 2 port and macOS Sierra.
In addition, it can be used to connect Thunderbolt-enabled displays — such as the Apple Thunderbolt Display and LG Thunderbolt 2 displays — to any of the Thunderbolt 3 (USB-C) ports on your MacBook Pro. However, using this adapter with an Apple Thunderbolt Display requires a power source, because the display does not provide power through the adapter.
Note: this is adapter is thunderbolt specific and will not work with Mini DisplayPort items