... ,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: ... is widely used as a secondary filter for clean room or clean factory workshop to cut down the load on ...