https://techcrunch.com/2017/11/16/htcs-vr-object-tracker-is-launching-in-december-for-99-99/

HTC’s Vive Tracker allows objects to be tracked in VR. It utilizes the same weirdly shaped configuration at the top of the HTC Vive controller, tosses a battery into it and a tripod mount and for $99.99 allows you to bring objects into virtual reality with you.

It’s been open to developers for a few months but now the device and some associated bundles are going up for pre-order today, shipping in mid-December.