Builder's Best PML320 Series - 4" Diameter Plastic Multi Louvered Wall Vent Hood is molded from durable polypropylene with free-swinging louvers that open easily for efficient airflow. The 11" tail design ensures a secure connection, and models with extended tails include aluminum trim plates for added stability. Lightweight and weather-resistant, this vent hood provides a reliable solution for wall-mounted venting applications.