This is a 60" x 20' Rosco #3404 N.9 Neutral Density Filter Roll. It is designed to absorb excess light such as strong sun coming through a window so that lighting can be balanced with it.
Cinegel filters are meticulously manufactured on a heat-resistant base polymer utilizing a patented deep-dyed technology for optical clarity. On-line computerized colorimetry continuously monitors color and density against strict standards, thus assuring a reliable and consistent product. Neutral Density filters reduce the level of exterior light and bring it within the exposure range of interior light levels.