Specifications: Material quality Laser Grade without boundaries and visible inclusions Range of Sizes Diameter : 5 - 76.2 +0/-0.10 mm Edge Thickness : 2 - 12 /-0.10 mm Thickness(radiused) : 2 - 5 /-0.05 mm Range of Effective Focal Length (EFL) 12.7-254.0 /- 2 % Clear Aperture (polished) 90% of diameter Surface Figure (power-irregularity) at 0.63 microns Plano: 1 fringe - 0.5 fringe per inch Radiused : varies dependent upon radius Surface Quality: Scratch-Dig 80/50, 60/40, 40/20 : per MIL-0-13830 AR Coating Reflectivity at 10.6 microns 0.25%