Quantity   Component name
1 × USB Webcam Used for getting the image data
1 × IR Passthrough filter Used to cut all visible light out before it enters the webcam
1 × IR LED Used to track position
1 × Pingpong ball Used as a diffuser for the IR LED
1 × Google Cardboard So you can see the virtual world
1 × High-end Android smartphone For the Google Cardboard. While I'm sure iPhones would work, I don't have one , and won't be building the software for them.