The Aprilaire 6508 is an 8-inch round normally closed ventilation damper designed specifically for use in low pressure systems (less than 1.0-in w.c.). This product is compatible with Aprilaire Model 1750 and 1770 dehumidifiers, ensuring optimal performance in your HVAC setup. Constructed from durable plastic, the Aprilaire 6508 damper effectively controls airflow, making it an essential component for maintaining indoor air quality.