Rain covers, also known as chimney caps or cowls, are designed to shield the top of your chimney from external elements. They come in various sizes to fit different chimney openings and are typically made from durable materials like stainless steel or copper to withstand harsh weather conditions. Installing a rain cover not only prevents water entry but also helps maintain proper airflow in the chimney, reducing the risk of backdrafts and improving overall ventilation. Additionally, rain covers can deter animals like birds or squirrels from nesting in your chimney, preventing blockages and potential safety hazards.