The Vive Facial Tracker is a very useful add-on for the Vive Pro that allows users to track facial expressions that can be displayed on a virtual avatar. The accessory is relatively inexpensive for Vive standards and does offer a functionality that could make a major difference to meeting other people in VR. Even though not advertised, the Vive Facial Tracker also works well with other major VR headsets like the Valve Index, but the accessory will have to be modded onto other headsets since official adapters are not available yet.