Solarrific&reg M9002 Patented Sun Block Nano Ceramic Film (3'x7')

I performed a quick and dirty test of this product, just to see if it performed as advertised. Without following the full installation instructions, I just taped it up over one of my bedroom windows that has two equal sized panes and sits right next to my computer workstation. Every afternoon the sun bakes me mercilessly through that window making it very uncomfortable to work. I taped it as close to the glass as I could get it.I then took a couple glasses of water and set them on the window sill, one in front of the sun blocked pane, and one in front of the bare glass pane. I let the glasses of water sit for a few minutes, then checked them with a standard kitchen thermometer.After 5 minutes, the sunblocked glass was 78 degrees, the bare glass was 82 degrees.After 10 minutes, 80 : 86After 15 minutes, 81 : 88After 30 minutes, 82 : 90So while this wasn't a completely controlled experiment, it was clear to me by both the temperature of the water, and by my comfort sitting next to the window, that the sun block film was doing its job.The appearance of the film, from the outside, when installed properly is barely noticeable. Just a slight tint. It doesn't look tacky or foil-like. And the same goes for the inside. It still passes plenty of light, (in fact if you're hoping for something like sunglasses effect, this isn't your product) and it's clear and distortion free.This is the wrong time of the year to test heat retention, so I can't speak to that claim.We don't run A/C in this part of the country, as there are only a few weeks of the year that the weather gets hot enough to require it. At the current price, without much sunny weather, this might be too much of an investment. However, if you live somewhere with a lot of sun, this could be a lifesaver.