I'm confused as to the point of this product. I use a USB-C adapter that provides me with 4K-capable HDMI, USB 3, gigabit ethernet and power pass-through that costs a quarter of the price of these Thunderbolt devices:
https://www.amazon.co.uk/gp/product/B01MZ0HFDG/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
According to the specs of that hub, it only supports 4K @ 30Hz, not 60Hz. In other words, HDMI 1.x rather than HDMI 2.0. There may be similarly priced HDMI 2.0 hubs with the same types of ports though. Also, since it has only one video port, for a dual monitor setup, you would be using two of the USB-C ports on your Mac instead of just one.
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