This Variable ND Kit A with Rota Pola Rota-Tray from Revar Cine darkens the entire image area from 2 to 8 stops by rotating a 138mm circular polarizer in combination with a 4 x 5.65" linear polarizer.

By using the rectangular 4 x 5.65" polarizer in an existing 4 x 5.65" tray, the rectangular filter remains fixed in place in the Rota Pola Tray and the 138mm geared circular rotating polarizer can be precisely positioned using the built-in dual gear design (0.8 pitch follow focus standard) to adjust between 2- and 8-stops of light loss. When installing, place the Rota Tray filter at the back and the rectangular filter in front, looking outwards.