On the negative "Micro Cooling Fan", the combination of anion and fan, as early as two or three years ago some brands market. But the practical effect is not very significant. According to some fan branded promotional materials, "Micro Cooling Fan" negative ion generation efficiency of only 10,000 -1.5 ten thousand per cubic centimeter, but the benefits to the body in the end how much is difficult to measure. So what different anions fan and previous products? Tested, "Micro Cooling Fan" efficiency compared with conventional fan products, has been "quantitative" to "qualitative change": its release negative ions of up to 500,000 per cubic centimeter, such a high concentration of negative ions, close to the forest, sea air anion content!