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The W-type filter increases the filtering area and reduces the structural resistance of the filter. It is characterized by large air volume, low resistance and long service life. Mainly used in clean ventilation and air conditioning systems. From medium efficiency (F6-F9), sub-high efficiency (H10-H12) to high efficiency (H13-H14), there are a variety of efficiencies for customers to choose. There are two types of W filter: box type and W type.