Air Flow Company, Inc., offers a variety of control, fire, fire/smoke dampers, to fit your mechanical needs.  We provide control dampers with both parallel or opposed blade configurations.  All of our low leak control dampers meet AMCA standard 500-D for Air Performance and Air Leakage.
Fire dampers meet NFPA 90 and UL555,
Fire/Smoke, smoke dampers meet NFPA 90 and UL 555S. 
Actuators and other accessories are available as well.