while producing frames. And it's made of thick galvanized sheet, which has high resistance to corrosion. The blade was shaped by new-tech distortion pressing with high strength aluminum press casting hub, which ensure it has the reasonable angle to Maximun the air flow. Along with the high-precisive micro-comput-ering manufacture-aiding system, the faction of the fan will be optimized 5 strict quality detection program: noise detection, vibration detection, trans-mission concentric function detection, balde velocity detection,whole machine effect detection,whole machine effects detection; 380V dedicated motor with three proofing and high performance. Adopting iron cone, ABS engineering plastic cone, all with easily dissembled safety net, which are optimal designed by CAD.