... Pocketr filter efficiency:F5,F6,F7,F8 3) Material:synthetic fiber 4) Washable Pocket filter,Medium filterF9 Synthetic fiber medium efficiency pocket filter Material ... : non-woven fabric (Synthetic fiber)Frame: Aluminum Alloy or galvanized sheet/plasticEfficiency:F5,F6,F7,F8, ... F9Application: It is widely used as a secondary filter for clean room or ...