https://arstechnica.com/gadgets/2018/05/googles-android-tv-dongle-is-real-but-it-wont-end-up-in-stores/

MOUNTAIN VIEW, Calif.—That Android TV dongle that showed up at the FCC last month is real, but it's not for normal consumers. Google had a Chinese OEM build Android TV into a pretty awesome Chromecast form factor, but it's only going to be used as a developer device—sales to general consumers aren't going to happen.

The dongle has been drafted into service as the "ADT-2," a developer-only Chromecast device. The specs are similar to the Amazon Fire TV 4K dongle or the Xiaomi Mi Box. It has an AMLogic 905X, 2GB of RAM, and 8GB of storage. It's just enough to get Android TV running and rendering 4K HDR.