MRC:
Those unusual or unique characteristics or qualities of an item not covered in the other requirements and which are determined to be essential for identification.FEAT
Special Features:
Clear aperature 90.0 percent of diameter; surface quali type 60/40; coating quali type 40/20; operating temperature plus 100.0 degrees c; optical quality flatness 3.0 to 5.0 waves per inch; parallelism 3 arc minutes; set consists of following densities - 0.10, 0.15, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90, 1.00, 1.30, 1.50, 2.00, 2.50, 3.00, and 4.00
