The Modine 5H0798020000 18 Inch 3 Blade 1/2 Inch Bore Fan is a high-performance component designed for effective air circulation in HVAC systems. With three blades, an 18-inch diameter, and a 1/2-inch hole, this fan is designed with precision to increase airflow within HVAC equipment. https://www.partshnc.com/18-3-blade-12-bore-fan