... with Shanghai Jiao Tong University on technology, External Rotor Fan Blade adopts advanced aerodynamic design, which is beautiful appearance, high ... efficiency.2,Fan rotor is directly with rotor and blade, that adopt dual-side dynamic balance, dynamic balance achieved ... of water-proof junction box for the user’s selection.Technical data about 450M series fan motorWHY CHOOSE DAYANGOver 15 Years ...