https://www.pcgamer.com/full-htc-vive-kit-with-upgraded-base-stations-is-now-available-in-the-us-and-uk/

HTC has been selling its upgraded Vive Pro VR headset for the past several months, though only as a standalone product—you had to either recycle your existing base stations and controllers (assuming you were upgrading from the first generation Vive), or purchase them separately. That is no longer the case. HTC and its retail partners are now selling the full Vive Pro kit with controllers and base stations included.

The two base stations that come in the Vive Pro kit are the upgraded SteamVR 2.0 models offering a total play area of 10m x 10m (32 feet x 32 feet). If that's not large enough, the Vive Pro supports up to four base stations to effectively double the play area.