Exhaust Fan Venturi Frame, For Blade Dia. 20 In., Height 24 In., Width 24 In., Max. Depth 8-7/8 In., Dia. Opening Required 22-1/2 In., Flange Width 1 In., Venturi Depth 3 In., Frame Material Steel, Frame Finish Galvanized, Dimension A 24 In., Dimension B 4 In., Dimension C 20-1/2 In., Dimension D 10 In., Includes Mounting Bolts and Slotted Motor Base To Accept 48 Or 56 Frame Motor