In addition to the fact that the grid I received was not what was shown on the advertising page, it was very poorly made. Also, as another reviewer described, the grille was covered in fingerprints. Also, I checked the grid in the spectrometer and there is no way to get sharp spectral lines. The best you can get is poorly lubricated lines. Based on past experience with grilles that look like advertised, these grilles appear to be satisfactory. But I didn't get that. Imagine a 35mm slide that is completely black except for the small image area (the grid in this case). Here's what I have.
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