These wall units work in any type of wall, 2x4 stud walls, 2x6 stud walls, brick veneer walls, block walls, and yes even 24" walls of south west United States. The Plexidor wall units include an interior aluminum frame, exterior aluminum frame and aluminum tunnel units frame. They can frame out up to 12" thick walls. Type: Doors Size: 16.5 x 21.25 Inches Color: Silver Color Mapping: Silver