AirPlay2 is an Apple protocol that allows wireless streaming media. It is only available Linn DS products equippped with Airplay2 hardware
The Linn DSM/HUB can take the audio stream via the "NetAux" input.
Airplay2 allows you to Group multiple Airplay2 devices (including Linn DS HomePod, Apple TV) to play in sync using iOS, Siri, Homekit, iTunes desktop (Windows & MacOS)....
