"220V Cooling Fan" copper tube housing, to ensure absolute vertical up and down two balls running off the blade to avoid problems (electronics market after the long-running fan buckle worn by most produced aluminum steps, usually stepped surface uneven, requires lathing evened out, up and down stairs easily cause deviation, upper and lower deviation ball, ball and retaining ring during operation will produce wear and tear, a problem arises that fan off, or stuck burning machine and a series of serious problem). 220V voltage type, current copper wire 0.07 0.09-0.11A, fan performance stability. (Electronic market to sell aluminum envelope fan, small wind, unstable easily burn-in)