DIAMETER: 0.857″+/-.005″
THICKNESS: 0.120″+/-.005″
PARALLELISM: 3 ARC MINUTES MAXIMUM.
FLATNESS: 10 WAVES/INCH MAXIMUM, 2 FACES.
SURFACE FINISH: 80-50 PER MIL-O-13830, 2 FACES.
MATERIAL TYPE/QUALITY: BK-7 GLASS, GRADE A, FINE
ANNEALED