This is a VR addon for mobile phone. Optimized for:Google cardboard lenses (45 mm focal, 25 mm diameter)  screen 130 x 70 mm (htc one max )  70mm eye spacingYet to come:Eye mask to fit between the device and the user eyes for more comfort and allow head strap. If you like the model and want to use it for different phone device,  and eye spacing, please ask and I'll try to help.Instructions:1) Depending on the print retraction of the 3D print, the Google Cardboard lenses may need side sanding. (I had to sand my lenses for 0.5 mm)  2) Sand the lens holes carefully, do not remove the three lugs.  3) Insert the lenses from the outside of the model pushing gently until the lens touch the lugs inside the lens holes.  4) Use the four slots on sides to insert a strap and hold the device in place.  Warning:  Use this model at your own risks.  This model can cause injury in case the lens cups apply too much pressure on the eyes.  Do not strap the device to your head without eye mask (yet to come).  Colliding an object while holding the device on the eyes may cause serious injury.  Do not look at the direct sun light with this device.