Plastic sheet acrylate base, 11.20 in. Lg, 1.13 in. H, 0.25 in. Thk, rectangular with lower lft cornercut to 0.75 rad., 7.70 in. Lg protrusion, 0.18 in. H, 0.06 rad max 2places, 4 holes 0.094 in. Diameter evenly spaced 3.200 in. Apart beginning 0.80 in. From lft end 0.48 in. Deep from lower edge of basic shape