Lense
grabcad
You can use it for Cardboard v2 file - without mounts The simplest file on GrabCAD I guess, but kinda looks cool.
Download Model from grabcad
With this file you will be able to print Lense with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on Lense.