Material alum alloy 6061-t6 per qq-a-250/1 (sm1870-27) or 5052-h32, per qq-a-250/8 (sm1870-21) 0.097/0.089 thk; finish chromate chemical film per mil-c-5541, class 1a; dimensions in inches, 3.32 lg, 2.57 to 2.59 wide; item shall withstand an axial extraction force of 8 pounds min