In an axial fan, the air enters and leaves in the same axial direction. The air volume in these axial fans is relatively high (dependant upon the frame, size and motor), and the pressure, measured in inches of H2O, is relatively low. The greatest variety of size and airflow performance is offered in axial fans, ranging in size from 25 mm to 172 mm with airflow of 2 cfm – 350 cfm. Axial fans are typically used in personal computers and office automation.