This Broan Model 643FA 8 in. Round Duct Aluminum Fresh Air Inlet Wall Cap improves your ventilation system. It acts as an air inlet. It also minimizes airflow loss for effective venting.. Brand/Model Compatibility: Broan, NuTone. HVAC application: Ventilation. Pack Size: 1. Product Weight (lb.): 2.5 lb. Returnable: 90-Day. Product Depth (in.): 12.75 in. Product Height (in.): 13. Product Width (in.): 12.5 in