The Graduated Neutral Density Kit Includes: graduated ND2 hard (1 F-stop) graduated ND4 hard (2 F-stops) graduated ND8 hard (3 F-stops) (3) cases for filters graduated Neutral Density (ND) filters allow you to reduce the amount of light reaching the sensor on a portion of your picture. This helps control the exposure difference between highlights and shadows for a more balanced exposure and dramatic effect. By rotating the filter-holder and adjusting the position of the filter up and down you can precisely control where the filter has an effect on the image.