https://www.theverge.com/ces/2018/1/9/16863336/milo-smart-speaker-hogar-controls-z-wave-zigbee

After the Amazon Echo started to get its owners hooked on smart home gadgets, Amazon went ahead and added Zigbee — a low-power smart home protocol — to the new Echo Plus, letting owners go even further.

Google still hasn’t tried that with the Google Home, but another company has come along and offered what’s essentially a bizarro version of the Echo Plus: it runs Google Assistant instead of Alexa, and it includes support for Z-Wave, a smart home protocol that competes with Zigbee.