POLIMA (Polarizador óptico de imagen)
POLIMA uses a Glan-Taylor prism which is a calcite cube that has been cut in half and assembled so that one of the two beams in the prism is eliminated. The polarization axis of the prism can be oriented relative to the plane of the image in one degree intervals. Besides the polarization analyzer, the system also has a metal head that contains a shutter, a wheel of optical filters, and a moving mechanism.
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This system has two filter wheels 8 positions each, allowing one to use a total of 14 filters (two positions are usually empty). This system can be used both with the 2.1m telescope and 0.84m telescope since there are especially designed mounts for each telescope.
The 
The filter wheel system "Italiana" (simply called "Italian wheel"), manufactured in Italy for the Brera Observatory, has two filter wheels, one with ten filter positions and another with nine (including one position for a polarizer). Usually