ventilation filters panel filter widely used in hvac system to filter dust ISO9001 CE EN779 popular in Europe and Asia ventilation filters Application: Filter dust , pre-filter through air filter programType: synthetic fiber foldaway filterFrame: aluminum, paper or galvanizedMedia: synthetic fiber Protect mesh: aluminum net or stainless steel netEN779 class:G2, G3,G4,F5Average arrestance:84%-90%( ...