Chromecast Audio -- assuming that's the name -- is said to plug into a sound system's headphone jack and lets you stream music from your phone by way of a wireless signal.
The device is part of Google's two-pronged strategy for getting its technology into your home. Some of Google's gear, such as its Nest thermostat, are on the cutting edge of connected home devices. Others, like Chromecast, turn devices like the television already in your living room or bedroom into smart gadgets.
Read more: http://www.cnet.com/news/google-wants-to-make-your-living-room-devices-smarter/