| Material | BK7 |
| Design Wavelength | 400-700nm |
| Dimension Tolerance | +0.0/-0.2mm |
| Thickness Tolerance | ±0.2mm |
| Surface Quality | 60/40 scratch and dig |
| Clear Aperture | >90% |
| Flatness | <2λ@632.8nm |
| Parallelism | <3 arc minutes |
| Coating | Metallic reflective coating |
| Coating Area | 0-270° |
| OD Tolerance | ±5% of OD Extremes |
| Part Number | Outer Diameter (mm) | Inner Diameter (mm) | Thickness (mm) | Optical Density | Design Wavelength (nm) |
| GNDF50-0-1 | 50 | 8 | 1.5 | 0-1.0 | 400-700 |
| GNDF50-0-2 | 50 | 8 | 1.5 | 0-2.0 | 400-700 |
| GNDF50-0-3 | 50 | 8 | 1.5 | 0-3.0 | 400-700 |
| GNDF100-0-1 | 100 | 8.3 | 2 | 0-1.0 | 400-700 |
| GNDF100-0-2 | 100 | 8.3 | 2 | 0-2.0 | 400-700 |
| GNDF100-0-3 | 100 | 8.3 | 2 | 0-3.0 | 400-700 |