During the cold weather months, windows become a prime spot for energy loss. Indoor Duck Brand Roll-On Window Insulation Kits create an added barrier between the outdoor air and your home's inside, helping to block drafts and air leaks that lead to high heating costs. This window insulator gives a clear finish and does not block the outside view. Each window insulation kit comes in an easy-to-use roll with a pre-taped top edge, which means no measuring needed - simply cut the extra film off once applied.