| Material | BK 7, grade A, fine annealed optical glass |
| S1 Surface Accuracy, Plano | ≤λ/10 flatness at 632.8 nm over the clear aperture |
| S1 Surface Accuracy, Concave | ≤λ/5 irregularity at 632.8 nm over the clear aperture |
| Surface Flatness, S2 | ≤λ/10 at 632.8 nm over the clear aperture |
| Clear Aperture | ≥central 80% of diameter |
| Surface Quality | 15-5 scratch-dig |
| Diameter Tolerance | Flat mirror: +0/-0.13 mm
Concave mirror: +0/-0.25 mm |
| Thickness Tolerance | ±0.25 mm (except 10B20, ±0.38 mm) |
| Wedge | Flat mirror, 30 ±15 arc min |
| Chamfers | 0.25-0.76 mm face width x 45° ±15° |
| Angle of Incidence | 0–15° |
| S1 Coating | UF.20, Rs, Rp >99%, 710–890 nm
Ts, Tp >95%, 488–532 nm, 0–20° AOI |
| S2 Coating | AR.14 broadband, multilayer antireflection coating
Ravg <0.5%, 430–700 nm, 0–15° AOI |
| Durability | MIL-C-675C, moderate abrasion |
| Cleaning | Non-abrasive method, acetone or isopropyl alcohol
on lens tissue recommended (Unknown type Newport.Step.Product.XRefElement) |