*Galvanized steel sheet frame, and the frame is one-off molded
*6 pieces stainless steel blades and the fan translations have all passed the experiment of homeostasis with big air volume, without deformation, no breaking, attractive and durable,

*Shutter: High strength hot-galvanized steel sheet shutter, with a centrifugal system which can ensure the shutter opens with the angle of 90 degree under all the condition.
*Belt Pulley: The V type belt pulley is aluminium magnesium alloy injection moulded, so it's light and high-strength.

*The belt ametabolic in a longtime.