Nikon's fast telephoto lenses (e.g. the 300 mm 1:2.8) have large front lenses to which no filter can be attached at the front. To solve this problem, Nikon has provided an opening and a holder at the rear of the lens into which standard 52 mm or 39 mm filters (depending on the lens) can be inserted.
Since polarising filters need to be rotated for them to work, Nikon's circular screw-in polarising filters are equipped with a mechanism that allows the polarising filter inserted into the lens to be rotated.
Fits for:
Autofocus:
AF-I 300mm f/2.8D IF-ED
AF-I 400mm f/4D IF-ED
AF-I 600mm f/4D IF-ED
More Info:
https://www.nikonimgsupport.com/eu/BV_article?articleNo=000048272&configured=1&lang=de
