While the physical build is decent for the price ($10–$25), manufacturers often forget to include a working QR code in the manual, or they print a code that is low resolution and unreadable. This leads to the dreaded "blurry edge" syndrome.
If you cannot find a code for your specific model, you can create a custom viewer profile: shineconhttps://www.shinecon.com Vr Shinecon Qr Code For Google Cardboard