US Sunlight 9910TR is an energy-efficient attic fan that can help improve airflow and reduce temperatures in your attic. It is designed for asphalt shingles, wood shake, or flat tile roofs with a minimum of 4/12 pitch. The fan is powered by a solar panel, so it does not require any electricity to operate. It is also equipped with a thermal switch that will shut down the fan when the temperature drops below approximately 65°F and turn the fan back on when the attic temperature rises to approximately 80°F. This helps to prevent the fan from running unnecessarily during cooler weather.