The Tiffen 5" x 6" 85N6 Filter is a rectangular drop-in filter designed for color correction purposes. It has a unique filter shape and a specific mount fitting for compatibility with certain camera lenses. The filter size of 5" x 6" ensures it can effectively cover a wide range of lenses to achieve the desired color correction effect. Ideal for professional photography and videography, this Tiffen filter offers quality performance in enhancing the color balance and overall image quality of your shots.