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 6135-01-472-9011
NSN 6320-01-125-3361
NSN 5996-01-426-1920
NSN 6320-01-540-4885
NSN 5895-01-448-6980
NSN 6645-00-176-5589
NSN 5910-01-108-6015
NSN 5905-01-546-8720
NSN 7035-01-216-4806
NSN 6145-00-420-6491
NSN 6320-01-039-5891
NSN 6650-00-784-9222