Easy Installation: Flex-Z Fast Bracket simplifies installation with a single-hinge bracket for easy positioning so you don''t need to access your attic to install the fan and includes options for 4'' or 6'' ducting

Customizable Airflow: This Energy Star-certified fan features Pick-A-Flow technology that allows you to select your desired airflow from 50, 80, 110 CFM; When fan senses static pressure, its speed is automatically increased to ensure optimal CFM output