Help identifying "Node 2" created on initial setup of Zooz USB hub

I just installed HAOS in VirtualBox on a Linux host. I had neglected to filter the USB hub so HAOS would see it. When I fixed that, and installed the Z-wave JS integration, it did find the ZST39 controller, but also added a “Node 2”. I have no other z-wave devices installed (yet) so I assume this is somehow related to the hub, but have no idea what or how. Can anyone give me a clue, or point me to the fine manual I didn’t read?

Thanks.