Diffraction grating set is intended for the demonstration of optics. It also can be used as a part of a set for optical wavelength definition. Contents: 1. Diffraction grate 100 slit/mm - 1 piece. 2. Diffraction grate 300 slit/mm - 1 piece. 3. Diffraction grate 400 slit/mm - 1 piece. 4. Diffraction grate 600 slit/mm - 1 piece. 5. Holder - 1 piece. 6. Packing box - 2 boxes.