Center 3 in. Diameter area shall be totally free of imperfections visible to the unaided eye
A transparent item of a predetermined size that permits unobstructed and undistorted view of a desired area. It may include a frame, have reference markings, grid lines and may be heat strengthened and/or tinted. It is generally used where safety, security, and/or the restriction of foreign matter are required, such as the visual examination of the inside of pressurized tanks, liquid sights, controlled liquid flow, and inspection of equipment enclosed in a housing. See window (as modified); scale, cathode ray tube; scale, plotting; window, metal; window, wood; and window panel, aircraft.
Classification: Pressed or molded glass articles, wired or not, for building or construction;leaded glass windows etc; formed multicellular or foam glass
NSN 5965-01-294-1396
NSN 6105-01-427-8439
NSN 5835-01-354-0566
NSN 6145-01-430-2784
NSN 6650-00-231-7843
NSN 5915-01-326-4293
NSN 6650-01-224-2555
NSN 6645-01-528-1635
NSN 5925-00-369-7747
NSN 6110-01-303-4669
NSN 5950-00-781-1943
NSN 6650-01-432-5461