https://www.theverge.com/circuitbreaker/2018/5/8/17333590/android-tv-4k-hdr-dongle-google-io-2018

It turns out that the Google-branded Android TV dongle that showed up at the FCC awhile back isn’t a consumer product. Instead, Google is offering it to developers as a reference product for testing their TV applications on. You can apply to receive one of the ADT-2 units from Google directly. The dongle supports 4K resolution at 60fps and is also capable of HDR playback. The specs are fairly middle of the road; an Nvidia Shield this is not.

Android Police notes that it uses the same chipset as Amazon’s Fire TV 4K dongle and has 2GB of RAM and 8GB of storage. It seems that the Android TV team built this gadget expressly for development purposes since the busted-old Nexus Player is no longer supported. But they made enough to give away the dongle as an I/O freebie and mail some out to developers. A voice remote is included, so using Google Assistant to pull up content is about as simple as it gets.