6" Universal Automatic Make-Up Air Damper with Pressure Sensor Kit 6" Universal Automatic Make-Up Air Damper with Pressure Sensor Kit; Interlocked make-up air damper systems meet IRC Code requirements for make-up air with range hoods over 400 CFM; Interlocked make-up air systems avoid wasted energy associated with barometric solutions and do not let unwanted air into the home during heating or cooling activities so air pressure is equalized for a well-balanced environment; Fresh air wall caps are required for use with Make-Up Air Dampers; Height 6.000; Color 0 Interlocked make-up air dampers provide outside air when required to keep the air in the home fresher by allowing the range hood to operate at optimum levels; Width 10.000; Depth 9.000; Weight 4.40; Operating System; Batteries Included; Batteries Required; Number of Batteries 0; Battery Type N/A; Language English; Assembly Required Balance indoor air pressure by providing interlocked make-up air without requiring a direct wire connection between the range hood and the damper Instead a sensor is attached to the exhaust duct to detect if the range hood is operating Slave dampers (MD6S, MD8S or MD10S) are interlocked to the main automatic or universal make-up air damper and open in unison for synchronized operation.