The item consists of a plastic laminate, specifically Type 1, Class 1 laminate, made from glass fiber cloth (No.181-75DE) in accordance with MIL-P-25421 specifications. It measures 1.75 inches in height, 3.57 inches in width, and 11.67 inches in length. The overall shape of the opening is triangular with radiused corners, and it is used on the base structure.