This Circular Polarizer Glass filter can be used to rule out and filter the scattering of light beam and make the light on the straight to your eyes, and then the view will be clear and natural. They can remove unwanted reflections from non-metallic surfaces such as water or glass and also saturate colors providing better contrast. The filter factor varies according to how the filter is rotated and its orientation to the sun.

10pcs Filter with Adapter & Holder for Cokin P seriesUS$40.69 US$31.69 |
Obviously at this price you're not getting the highest optical quality. However, it's pretty good and a valuable addition to you're camera bag. Recommended.
If you have an autofocus camera and shoot photos outdoors, this filter needs to be attached to the end of your lens.
Ottimo polarizzatore di qualità, lo consiglio molto.
Good for what it is, very good price but this isnt the same glass nikon uses on its filters, having said that an amateur or semi pro photographer will not be able to tell the difference unless pictures are really really blown up. Get it.