A metal fireplace chimney damper can warp or break over time and use. This causes a cold air draft and odor to enter your home, and heat to escape. The Chimney Balloon, also know as a Chimney Pillow, is a removable & durable device that has been saving families home heat for more than 20 years. It stops airflow, odor, and debris from flowing through your chimney. This prevents chimney odor & cold drafts from entering your home, and prevents heat from escaping.