The USB-C Digital AV Multiport Adapter lets you connect your USB-C or
Thunderbolt 3 (USB-C) enabled Mac to an HDMI display, while also
connecting a standard USB device and a USB-C charging cable.
adapter allows you to mirror your Mac display to your HDMI-enabled TV or
display in up to 1080p at 60Hz or UHD (3840 by 2160) at 30Hz. It also
outputs video content like movies and captured video. Simply connect the
adapter to a USB-C or Thunderbolt 3 (USB-C) port on your Mac and then
to your TV or projector via an HDMI cable (sold separately).