Filtering medium of W mode filter is glass fiber filter paper or polypropylene fiber filter paper and its character is big air flow,low resistance and long service life.W mode filter is mainly used in clean ventilation system and has two appearance modes of V mode and box type for customers'choice.Many kinds of efficiencies,from medium efficiency(F6~F9),Sub-high efficiency(H10~H12)to high efficiency(H13~H14),and adhesive spray modes are provided to customers for choice.