Docks abound for USB-C connectors, whether for USB-only devices or for those—like all Macs released in the last few years—that sport the very high-speed Thunderbolt 3. The Other World Computing Thunderbolt 3 mini Dock offers the lowest price so far for offering support via Thunderbolt 3 for two 4K displays. If you need to add two displays and want to preserve USB-C ports, then this dock fits the bill.
The two HDMI 2.0 ports can each handle up to 4K video at 60Hz. You can also use HDMI adapters and cables to work with other compatible standards, like DisplayPort.
The dock includes just three other ports: one high-speed USB 3.0 (Type A), one USB 2.0 (also Type A), and gigabit ethernet, which tested at gigabit speeds even with all ports occupied, as it should. However, I was unable to get the ethernet port to appear immediately on my Mac, which may be related to previous Thunderbolt docks used with the computer. After a standard restart, however, the ethernet interface appeared as expected in the Network preference pane and tested perfectly.
