That's a standard projector mount. Similar would be Chief RPMAU. Peerless PRGUNV. You can see the projector in use has 3 or 4 mounting points for the mount instead of one single 1/4" threaded hole like some models do. You can also go as cheap as the QualGear Pro projector mount, but it's not nearly as good as the Peerless or the Chief...
https://www.amazon.com/QualGear-QG-PRO-PM-50-B-Pro-AV-Threaded-Accessory/dp/B01B1JEBM6/ref=sr_1_4

But, it's a ton cheaper.