Noise is increasingly focused on a lot of players, for the fans who are the noise from the fan. A little bit of difference between the fan and will not cause a big impact, but to know that in fact the tiny vacuum region may be the biggest source of noise, many manufacturers are in the upper and lower blades no small effort, mainly through some fancy small reformed to achieve better mute the diversion effect. On "Micro Cooling Fan" safety requirements, national standards set forth very detailed, consumers can be a simple test. Eligible fans, general adult fingers can not touch the grille and the front edge of the blade, families with children should choose dense fan grille.