Great addition to my new apartment. I have 2 very large windows and 4 smaller ones that let in a lot of sun and heat. Living in AZ, these rooms get very hot and make my AC run constantly! So these are life savers and make a great difference! I would have given them 5 stars, however they are not quite the black out I was expecting compared to the others I have. Some light does still make it through, something to keep in mind if you want complete black out.