... fire-proof material, RD signal (Stall warning), FG signal(Detect fan speed value), warter proof and so on.CEETIFICATE:CE: have been ... . If it connect connecting the DC fan through the ADC cooling module, the wind speed of the air volume improved significantly, ... maintenance-free. Oil and gas pollution-free, The fan use import high-speed, thermostability ball bearings ,hundred percent guarantee non-oil ...