From video description:

“In this Bigscreen Beyond teardown video, we give a detailed look at its inner workings and showcase what makes it so special.

Bigscreen Beyond, the world’s smallest VR headset. Micro-OLED displays with 2560 x 2560 pixels per eye, custom pancake optics, SteamVR tracking – all in an unbelievably small form factor weighing just 127 grams. And for ultimate comfort, each headset is custom-built for each customer using a 3D Face Scan.”

https://www.youtube.com/watch?v=1of-29B804U
https://www.bigscreenvr.com/