<http://schema.org/primaryImageOfPage>
"http://media.treehugger.com/assets/images/2012/05/LED-1.jpg"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.treehugger.com/slideshows/gadgets/how-to-make-3d-printed-circuit-boards-and-an-led-flashlight/>