Not sure what needs to be written. It is a “space-age” radient heat barrier that is being sold to deter heat transfer between the attic and living space. Based on the demo I once saw at a presentation, it appears to work pretty much as advertised, but whether it is worth the price is another story. They wouldn’t sell the material only and wouldn’t say how much it costs until they do “an in-home survey”. I declined. Here is a DOE web site on the subject : http://www.ornl.gov/sci/roofs+walls/radiant/index.html
I say it impedes my ability to move around in and thoroughly inspect the attic.