ELI5: Explain Like I'm 5

Window film

Window film is a thin plastic film that you stick to the inside of your window to keep out hot and cold air. It helps make your home warmer in the winter and cooler in the summer, saving you energy and money. The film is usually made of special materials that block sunlight and give the window a slightly reflective look. Once the window film is in place, it will help keep your home more comfortable and help keep your energy costs lower.
Related topics others have asked about: