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 6620-00-605-8656
NSN 5950-01-389-7921
NSN 5835-01-088-4676
NSN 5975-00-165-5834
NSN 6240-00-548-3992
NSN 5855-01-580-4634
NSN 5996-00-543-1566
NSN 6150-01-483-7713
NSN 5905-01-147-5328
NSN 7035-00-079-7189
NSN 5965-01-526-4758
NSN 6135-01-195-5343