With the first wave of modern virtual reality headsets now out in the wild, the number of people who have yet to try the HTC Vive or any of its competitors is quickly shrinking. Although a large number of people have now tried or purchased a Vive, the same can definitely not be said of Valve's early and extremely rare internal prototypes. First shown off at Steam Dev Days 2014 and GDC 2015, these early prototypes were extremely rough, hacked-together pieces of equipment designed exclusively to test functionality and new ideas. While it's been a while since we've seen any of these headset concepts shown off or discussed by Valve themselves, YouTube channel "Make" recently uploaded a new video featuring Valve engineers Alan Yates and Monty Goodson as they show off and talk through a number of different designs. As shown, the 15 minute video highlights many of the different and usually cumbersome concepts that Alan, Monty, and the SteamVR hardware team created as they developed almost all of the technology behind the HTC Vive, the controllers, and the Base Stations from spare parts and raw ingenuity. It was clearly a long and complicated process that we're very happy to have been given just a little bit more insight into. Check out the video above and let us know what you think in the comments below!