Highest quality,lowest price,manufactor,OEM Size:37mm-86mm material:optical class,metal circle. 1.Size:37mm,40.5mm,43mm,46mm,49mm,52mm,55mm,58mm,62mm,67mm,72mm,77mm,82mm,86mm,etc. They are used for color correction of different light sources when using color film, or for controlling contrast with Black&White film.Color correction filtersare important as color films do not have the flexibility of ...