The new Google Chromecast Ultra supports 4K and Dolby Vision.  It comes with an Ethernet port built into the provided power supply for more reliable high bandwidth video streaming.  This wired port power supply is also available as a separate purchase for the current Chromecast.  Buy for $15 @  google.com

Google’s Chromecast Ultra launch video:

The new Chromecast will cost $69 and is available in November.  The current Chromecast 2 is available for $35 and can be found for less on sale.
More details @ google.com