The filtration has multiple layers, usually composed of a combination of various filter materials, which helps capture particles of different sizes and supports air purification. Odorless design: the filter materials are treated so that they are unlikely to produce unpleasant smells during operation, helping to maintain natural air. Electrostatic mechanism assistance: some filter materials use an electrostatic electret process, which can help adsorb even smaller suspended particles. Good dust-holding capacity: the multi-layer structure can accommodate more dust and particles, which helps extend the filter's service life. H13 H14 Air Purifier Equipment Deep Pleat Air Filter, Manufacturer: YLxshop