Seeking four precision optical wedges. Two are 6 inches in diameter and two are 12 inches in diameter. All must meet the following specifications: 1. Wedges shall be uncoated and unmounted; 2. The material shall be fused silica.; 3. Wedge angle 15 degrees +/- 1 degree ; 4.Thin dimension not to exceed 0.75 inch (for the 6 inch wedge) or 1.0 inch (for the 12" wedge).; 5. Dimensional tolerance: +/- 0.010 inch.; 6. Surface Flatness Specification: Lambda/10 @ 632.8 nm over clear aperture.; 7. Clear Aperture: 90% central at 20 degree angle of incidence.; 8. Surface Quality: Scratch/Dig 10-5; 9. Edge Chamfers: Less than 0.030 inch facewidth, not to encroach on clear aperture.; 10. Transmitted Wavefront Error: Lambda/10 or less.