'ROUGH-CUT' VERTICAL WALL - Rigid polyurethane foam - Gray primer base finish. Weathering recommended. Matching vertical wall with buttress column. Overall dimensions: 11-1/2" H x 7-1/2" W x 1/2" thick. Column Buttress cast into wall. 1/2" dado cut inside groove behind buttress allows interlocking of adjacent walls. Easy to make step walls.