... offer, 1 year for the whole machine.High precision system is assistant by computers, which ... fan. Ten strict procedures that consist of airflow test, noise test, libration test, drive concentric test, blade RPM test, electric ... spare parts test, They assure the quality of the fan.ModelBlade/mFrequency/HZMotor Speed(r/min)Capacity ... wall-mounted push-pull centrifugal ventilation fan for industry