The eFlow USA Constant Airflow Regulator is UL-Classified and factory-calibrated to provide non-powered automatic air balancing. The regulator offers energy savings, better IAQ, and the elimination of stack effect for commercial and residential buildings. It is a low-cost solution for balanced ventilation systems. The regulator eliminates the need for onsite balancing. It is available in 3-inch to 10-inch diameter, features 10 to 500 field adjustable CFM and has a pressure operating range of 0.08-inch WC (20 Pa) to 2.4-inch WC (600 Pa). eFlow USA offers a six-year warranty for the regulator as well.