4'' USB Cooler Fan 1.DC brushless motor 2.Voltage:DC 5V ... Ultra-thin design,dexterity,easy to carry 4'' USB Cooler Fan1.DC brushless motor 2.Voltage:DC 5V 3. ... .Ultra-thin design,dexterity,easy to carry5.Ultra-quiet fan for office, home 6.Portable,free angle use,great ... occasion. 8.Fan occupies small room, stable structure, easy to place. 9.Sofe wind, cool and refreshing, comfortable. 4'' USB Cooler Fan