Do you know how to identify the quality of "Tiny Cooling Fan" is good or bad it? Today around this problem, small as you simply explain. I believe that many buyers and cooling fan cooling fan manufacturers are aware of, "Tiny Cooling Fan" oil-bearing and ball, that first of all we start to identify the bearing, oil prices lower bearing turn voice is small, some manufacturers providers within the oil-bearing plus Teflon, making the fan also has a ball bearing reliability, and then sell high. Ball bearing "Tiny Cooling Fan" oil-bearing noise ratio, the price is relatively more expensive, but more reliable, universal life longer than the oil bearing.