The louver type ventilating fan is the most widely used ventilating fan, and is mainly composed of auxiliary components such as an electric motor, a fan blade, a wind frame, a panel, a blind, and a dedicated wire switch. The motor generally uses a single-phase capacitor to operate an asynchronous motor. A hood fan is also used for the ventilator below 150mm. Fan blades are generally injection molded from ABS and AS plastics, which are light in weight and high in strength. The wind frame is usually made of sheet metal stamping and spot welding, and is also injection molded from plastic. The panels are injection molded from plastic. Shutters are usually stamped from sheet steel or tinplate. Screen Guard,Ultra-Thin Screen Protector,Full Coverage Screen Protector,TPU Hydrogel Screen Protector,TPU Film,Screen Protection Film Shenzhen Jianjiantong Technology Co., Ltd. , https://www.mct-sz.com