This series of fan is composed with cylindrical aluminum alloy ,steel outer covering ,plastic steel van andelectrical machinery.Using the technique of flange installation ,it owns the characteristics of smalvolume,light weight ,convenient fixation, along with the excellent functions of big wind-force, high pressureless noise,litle vibration and reliable running.This fans are mainly used in electrical installations,medicaapparatus, printing machinery,refrigeration plant,electric welder,power supply equipment,numerical controinstrument,computers, communication satellite,domestic appliance and automatic facilities. it mostimportant effectis ventilation and radiation.