... 3.reliable operation 4.excellent functionin cross flow impellerFan material: aluminum alloyBearing: ball bearings or bearingMotor capacitor type: AC, AC, ... .Cross flow fan using aluminum alloy materials, light weight, large air volume, low noise, high strength, low vibration, high Wen Jia, long life ... : 110 / 220V 40 / 42W, blade diameter 50MM, length 42CM:. high quality cross flow impeller