Features: light weight, versatility, compact, fold-fold increase effective filtration area, large air volume, low resistance, high dust holding capacity, easy to replace materials and performance: box material: cardboard support network: galvanized mesh or aluminum diamond mesh (rear folding metal mesh filter attached) Media: woven Efficiency: G3-G4, maximum temperature 80 ℃ apply to: Central air conditioning and central ventilation system pre-filter, gas turbine and compressor inlet air pre-filter, clean room return air filter, high efficiency filter partial pre-filtration device