Two 4K Displays: This USB C to Dual 4K HDMI Adapter supports up to two 4K@60Hz HDMI displays, when connected to hosts that support the DisplayPort 1.4 Alt Mode. For hosts that support DisplayPort 1.2 Alt Mode, the adapter supports two 4K@30Hz displays. Wide Compatibility: This adapter is compatible with USB Type C or Thunderbolt 3 hosts running both the Windows and macOS operating systems, with support for DisplayPort Alt mode. Supports MST, SST, And Mirror Modes: This USB C to Dual 4K HDMI Adapter supports the Multi Stream Transport feature on Windows hosts, which allows each display to show content different from each other and different from the main host screen. It also supports the Single Stream Transport (SST) and Mirror display modes for both Windows and macOS systems. SST allows the external displays to show content different from the main screen, but identical to each other, while Mirror mode has the two external displays showing the same content as the main host