1.Fan frame: it is formed in one step due to the use of advanced automatic processing technique, the thick zinc coating (150g/m2) ensures great corrosion resistance, the bottom outlet design makes fan structure more reasonable. 2.Belt pulley: The V-shaped hub made of aviation aluminum alloy is light, tensile, high-strength, and unlikely to break. 3.Fan blade: six stainless steel blades which are formed in one step are aesthetic, durable and resistant to deformation, the blade passed the dynamic balance test and its reasonable angle ensures maximum air flow and minimum noise. 4.Shutter: High strength hot galvanised plate, the automatic opening-closing device makes it possible to open and close louvers completely, maintain a 90-degree opening angle to ensure louvers are windproof, rainproof and dustproof. 5.Shutter opening-closing device: Made using tensile industrial nylon and injection molding technique, the device features high strength and long life. As the guide bar is inlaid with metal sheet, its strength is greatly increased, contributing to the reliability of the opening-closing device. 6.Motor: energy efficient, 3C approved, IP54, class F insulation. 7.Belt: Imported B type belt is long lasting, deformation free, and requires no maintenance.