When consumers buy "Micro Cooling Fan", to look at the instructions to see if the mandatory certification quality system certification, whether there is inspection standards certification; and now promote "green carbon", depends on whether the national level energy efficiency standards. Noise: "Micro Cooling Fan" making noise of the main components of the motor, in the selection of fan must listen whether the noise when the motor is running, to see it in operation whether jitter is stable; good motor let you in quiet environment, only to hear the wind, "whispers", ultra-quiet fan blowing air is good. Safety requirements for electric fans, the national standards set forth in a very detailed, consumers can be a simple test. Qualified fan, general adult fingers can not touch the fan grille and front, families with young children should choose grille dense "Micro Cooling Fan".