Hat Channel Motorized Damper, Voltage 100 to 240, 50/60 Hz, Overall Square 11 3/4 in, Sq. Opening Required 12 in, Frame Less Flange 9-3/4 sq in, Free Area 0.372 sq ft, Motor Bracket Extension 11 1/2 in, Flange Width 1/2 in, Extruded Aluminum, Mounting Position Horizontal or Vertical, Number of Panels 1, Power Open, Spring Return, For Use With Duct Work In Volume Control Intake or Exhaust Applications