The ESP Window and Door Closed Cell Foam Weather Seal 4.8x9mm helps to keep your home warmer in winter and cooler in summer. Made from closed-cell polyurethane foam, it fills gaps around doors and windows to eliminate energy loss and reduce your gas and power bills. As homes settle and move slightly over time, gaps can develop. These gaps let cold air in during winter, and hot air in summer. Similarly when we use heaters and air-conditioners, these gaps let warm air out in winter and cool air in summer, costing us money. With a self-adhesive backing, the ESP Window and Door Closed Cell Foam Weather Seal is easy to install yourself around your windows and doors so you can start saving money today.