Thoroughly inspected by Toby.
Note: ThunderBolt 2 isn't the same as Mini DisplayPort. If you want to connect your screen (with Mini DisplayPort) to your MacBook, use a ThunderBolt 3 to Mini DisplayPort adapter.
With this Thunderbolt 3 (USB-C) to Thunderbolt 2 adapter, you can connect Thunderbolt (2) devices to your new MacBook with USB-C/Thunderbolt 3 port. Think external hard drives or an extra screen with Thunderbolt or Thunderbolt 2 connector, for example. Because it's bidirectional, you can also use this adapter to connect new Thunderbolt 3 devices to an (older) iMac or MacBook with
a Thunderbolt or Thunderbolt 2 port.
This is an original Apple accessory.