Google has published the instructions for making your own viewer from a couple of dollars worth of parts. But the Google cardboard kit was ready to assemble and took you only about a minute to fold where indicated, stick a few tabs into slots, and voilà - it was ready to nestle my phone inside and run the Cardboard app.
This lens is 25mm diameter with 45mm focal lenght.
It is professional for virtual reality glasses.
It is a simple and inexpensive for DIY Google cardboard.
With Cardboard App, you can DIY a virtual reality glasses, like Oculus Rift VR glasses, and you can control your phone with the magnets
Quality tested & guaranteed by many customers from different countries.