In the 9072DS, the grating in the second monochromator is arranged such that it reverses the spectral dispersion of the first monochromator. This leads to a spectrally homogenized beam at the output port of the second monochromator and greatly reduced stray light, ideal for spectroradiometry, Raman or UV measurements of solar radiation. The arrangement of the 9072DS allows it to act either as a tunable bandpass filter or a tunable notch filter. Arranged as a tunable bandpass filter the bandpass of the device is determined by the width of an intermediate slit. When arranged as a tunable notch filter the width of the notch is determined by the physical width of an opaque notch placed at the intermediate slit position. The 9072DS can also be used to pass or filter out several selected wavelengths by using a custom intermediate multi-slit mask instead of a single width intermediate slit. Grating holders are not included