Material aluminum alloy, qq-a-250/11, t6; surface treatment chemical film, mil-c-5541, cl 1a; o/a dim. Lg 1.214 in., w 1.040 in., thk 0.017 to 0.023; one side-corners chamfered 0.120 by 0.120 in. W/notch of a 0.175 in. Radius measured 1.214 in. From opposite side ctrd at 0.470 in.