"DC Fan" is the role of airflow away accumulated on the cooling fins of the heat. The larger the fan air flow, air flow per unit time the greater the cooling effect is more significant. In general, the fan current, the higher the fan speed. But the decision depends not only on the amount of wind speed also depends on the angle of the fan page. Under certain circumstances the angle of the fan page, the higher the speed, the higher the amount of wind. Typically fan specifications are 6cm, 7cm, 8cm, 9cm, 12cm minority radiator started using large diameter fan, fan size and 80mm usually defined as four-digit identifier, such as 8025 for diameter, thickness of 25mm fans.