Air Filters are available up to 4000M3hr. with face velocity 1.5MSec. to 3MSec. initial pressure drop 6Pa to 25Pa and average efficiency up to 99.9998% filter class G1 to U15 ( BS BN 779 ). The filters are fabricated under exacting condition to meet the rigid specification of international Test Standards as per U.S. Federal Standard 209 B.