4-72/3.6a blower fan: 1,iron steel 2,Y100L-2 motor 3,3kw 4, ... high quality 4-72/3.6A blower fan: 1.Application and characteristic*It is used for indoor air ... control .*It is belongs to medium pressure, big flow centrifugal fan. It’s impeller is made of retroverted wing shape vane ... arc front disc and plate back disc. The kind of fan has high efficiency ,low noise .It is sturdy and durable ...