Special Features
Polish surface quali type 80/50 scratch/dig per mil-o-13830; surface irregularity less than or equal to 1/4 wavelength peak to valley at 632.8 nm; surface flatness less than or equal to 1/2 wavelength peak to valley at 632.8 nm; clear aperature to be 2.35 in vertical direction and 2.60 in horizontal direction
