The Marumi 40.5mm EXUS Circular Polarizer Filter helps to reduce reflections and glare by filtering out light that has become polarized due to reflection from a non-metallic surface. This results in a noticeable increase in the saturation of skies and foliage, as well as clearer imagery when photographing in hazy conditions. A circular polarizer differs from a linear polarizer in that it supports full use of a camera's autofocus and auto exposure functions.

This filter features an anti-static coating that also provides water and oil-resistance to protect the filter from dust, dirt, and moisture and to also aid in cleaning. The thin filter ring design is ideally suited for use with wide-angle lenses and features multiple light-blocking ridges, a satin finish, and a black ink coating to provide a surface reflectivity of less than 0.6% to reduce the likelihood of lens flare and ghosting. Additionally, the male threads of the filter ring are coated with Teflon to help eliminate filter jamming and promote easier installation and removal from lenses.