Derived from the XO-1 viewfinder. http://www.thingiverse.com/thing:330 "This is a viewfinder that plugs into the USB slot of an OLPC XO laptop to help kids align the forward-facing camera." The XO-4 has a different USB port configuration than the XO-1. I modified the original .STL file to reflect the changed port arrangement so this Thing would work with the XO-4. This thing was made with Tinkercad. Edit it online https://tinkercad.com/things/2SmRiO7mPlNI printed this on a Thing-O-Matic with an MK6+ nozzle at .3 mm layer height, 5% infill.