4.438 in. Diameter hole in center of window
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 6150-00-934-7853
NSN 5930-00-998-5764
NSN 6110-01-501-6980
NSN 6220-01-256-6400
NSN 5925-01-131-4377
NSN 5915-01-290-0470
NSN 5985-01-116-6429
NSN 5930-01-114-3065
NSN 6105-01-606-8185
NSN 6135-01-482-7901
NSN 6645-00-163-9580
NSN 5996-00-881-9677