... person: Teresa Skype:hx-fan QQ:2780673541 1.What is a DC Fan? DC fan is usually powered by 3v,5v,12v,24v,36v ... ,40mm,50mm,60mm,70mm,80mm,92mm,120mm,150mm,200mm. 2.What is a bearing? Fan bearing includes Sleeve Bearing and Ball Bearing,life ... expectancy of sleeve bearing fan is 30000hours,while ball bearing is 50000hours or more. 3.What's can we do? We are ...