Cokin X306 is a professional filter system that provides photographers with a wide range of creative possibilities. With its large filter size of 170x130mm, the X306 can be used with a variety of lenses, including wide-angle lenses, without vignetting. The system's unique Ring Locker System (RLS™) keeps filters parallel to the lens and can secure the holder in a certain position or allow it to rotate freely. The X306 is also reversible for use with polarizers, minimizing the risk of vignetting when using wide-angle lenses. Additionally, the modular bellows eliminates unwanted reflections.