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. No odor: odor is the smell of varnish coating "Micro Cooling Fan" on the copper produced at the time of the operation, in the purchase of fans have to smell it, to see this paint is environmentally friendly, whether through quality testing, so that you enjoy the cool air in the fresh air.