| Variable Neutral Density Filter | |
| Material | BK7 |
| Diameter Tolerance | +0.0/-0.2mm |
| Clear Aperture | >90% |
| Thickness Tolerance | ±0.2mm |
| Surface Quality | 60/40 scratch and dig |
| Flatness | <2λ@632.8nm |
| Parallelism | <3 arc min |
| Chamfer | |
| OD Tolerance | ±5% of OD Extremes |
| Design Wavelength | 400-700nm |
| Coating | Metallic reflective coating |
| Coating Area | 0-270° |
| Wavefront Distortion | <λ/8@632.8nm |
