M-D Polar Block Clear Plastic Glare Control Window Shrink Film 62 L x 42 W in. (Pack of 6)The MD Polar Block Window Insulation Kit is fitted around the entire window to avoid cold air draughts and frost build up. With a thickness of 0. 75 mils, this shrink film provides dead air space to boost insulating R Value up to 90 percent. It's a clear film that's simple to apply with a hairdryer. Nine sheets of window shrink film with mounting adhesive are included in each bundle. This window kit keeps you warm in the winter by preventing heat