FSD-AF and F/S-AFM is a series of BAS-CVS UL/ULC classified combination fire & smoke dampers manufactured with “Airfoil” type blades. These dampers have been investigated for fire protection rating of 1-1/2-hour or 3-hour (UL555) and at minimum velocities of 2000 feet per minute at 4 in. w.g. of static pressure for the range of “3V” blade models and maximum velocities of 4000 feet per minute at 6 in. w.g. of static pressure for the range of “Airfoil” blade models for a leakage rating as defined under Class I or Class II (UL555S).