1.filter material: Synthetic fibres 2.efficiency: G3(EN779):weight80-90% G4 (EN779): weight>=90% use: Comfortable ventilation and air conditioning system of filters; Air conditioning system clean room etc.outer frame : outer frame: aluminum alloy or galvanized, 21mm thick flangefilter material: Synthetic fibresinner frame: Galvanized wire or box + galvanized clip or aluminum clipefficiency: G3(EN779):weight80-90%

            G4 (EN779): weight>=90%

continuous operating temperature:<=70resistance to wet:<=100%RHsuggest biggest end resistance:250pa