The Cokin Filter X022 Blue (80C) is a colour correction filter that adds a cool colour tone to your images. Warm tones become more blue. With a size of 130 by 170 millimetres, the filter is suitable for use in the Cokin BX-100A filter holder. The 80C addition means that this filter can correct colour temperatures between 3800 and 5500 degrees Kelvin. Think for example of reportage flash units