| LH 22.45 | Diffraction Grating (Hilger & Watt Type) 15000 Lines Per Inch, (600Lines/Mm) (Routine Quality) |
| LH 22.46 | Diffraction Grating (Hilger & Watt Type)15000 Lines Per Inch, (600Lines/Mm) (Superior Quality) |
| LH 22.47 | Diffraction Grating (Hilger & Watt Type)25000 Lines Per Inch, (1000Lines/Mm) (Superior Quality) |
| LH 22.48 | Diffraction Grating (Hilger & Watt Type) 2500 Lines Per Inch, (100Lines/Mm) (Superior Quality) |