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 5855-01-089-2248
NSN 5945-00-893-6677
NSN 6650-00-879-5834
NSN 6320-01-308-0009
NSN 2925-01-224-1885
NSN 6135-01-366-9633
NSN 5910-01-106-6971
NSN 6620-00-505-5031
NSN 6135-01-545-6582
NSN 5960-00-239-3054
NSN 6135-00-856-1343
NSN 5950-00-197-7705