... belt 3.Energy saving motor 4.Seven strict quality test Jienuo believe thatToday the quality of our product is ... mini. Noise. All fan blade through dynamic and static test, the banlance difference is no more than 3g 6. ... strictly quality test process: noise test, vibration test, concentric performance test, fan blade turning speed test, input air test, vehicle efficiency test and motor current test.11. ...