The living room in my house is open to the upstairs and there are large windows that let in a tremendous amount of natural light....and heat. The sun shines through these windows all day long. This has caused my air conditioning to constantly run, all day long, from late Spring to early Fall. I thought I had done a lot of research before calling Carolina Premier, but apparently not. Michelle came out to my house to provide a quote and also brought with her an entire demonstration kit and different grades of film. She explained to me about 3M's window film and how it was far superior to other brands, the warrenty, everything. I had no questions by the time she was through. I was very impressed! (doesn't happen that often) She left several samples with me which i taped to the window to look at for a few days before making my decision. I called back and set up my appointment. The installers did an awesome job! I highly recomend you give them a call if you are in the market!