This standard rotation 18″ fan clutch fan is designed to replace the factory fan clutch, with an 8 hole center hub fits most OE fan clutches. Manufactured from sturdy steel hubs and fan blades, it produces maximum airflow. Comes in durable, attractive black powder coat finish. Steel fan blades give maximum full-time airflow. Black powder coated finish. 18″ standard rotation design. Rated up to 8,000 RPM. Dimensions: Diameter 18″, Flange bolt circle 3″ to 3-1/4″, Flange diameter 2-3/8″ to 2-5/8″, Depth 2″. Mounting surface to front 1″. Mounting surface to back 1″.