Google partnered with Huddly to develop this camera system (and the two companies also collaborated on previous Meet hardware projects).
These additional units only feature the speakers and microphones, without the additional AI hardware since all of the processing needs to be done centrally.
For $2,999 you get a complete set with one standard camera, soundbar, microphone pod and controller, and if you have a very large room, you can opt for the $3,999 version with the additional soundbar, two microphone pods and the Smart Camera XL