| Neutral Density Filter-Reflective | |
| Material | B270 Glass |
| Diameter Tolerance | +0.0/-0.2mm |
| Clear Aperture | >90% |
| Thickness | 2.0±0.2mm |
| Surface Quality | 80/50 scratch and dig |
| Flatness | <2λ@632.8nm |
| Parallelism | <5 arc minutes |
| Chamfer | Protective<0.5mm×45° |
| OD Tolerance | OD±10% |
| Coating | Metallic reflective coating |
