AlexNZ Thingyverse member has created a 3D printable GoPro camera stereo rig that is capable of being used to record 3D footage that can be then viewed on your 3D TV or virtual reality headset.
As you can see from the image above the rig requires to GoPro cameras and the cameras must be the same model for it to work correctly so paired together either 3 and 3 or 4 and 4 or 3+ and 3+ for best results.
Its creator explain over on Thingyverse :
There is a first version of rig hidden inside .blend file (with cameras stand side by side) but i not recommend that one: final version (with one upside down camera) give better results.
Jump over to the Thingyverse website to download the files to print your own GoPro 3D rig or modify for your needs.