Wedge material glass, jan-g-174, bsc-2, 517-645; housing material aluminum alloy; surface treatment grey enamel; o/a dim. 5.000 in. W, 5.000 in. Lg, 1.500 in. Thk; w/hardwood carrying case; fixed std; designed to deviate azimuth and elevation; 20.0 sec nom deviation; aperture 3.000 in.