This Lee 4x6 Graduated Neutral Density Resin Filter Set (0.3, 0.6,0.9 Hard Edge) is a set of three hard grad ND filters in grades of 0.3 (1 stop), 0.6 (2 stops), and 0.9 (3 stops). These filters allow you to balance the light intensity of one scene with another, creating a beautiful tone throughout your entire image. Hard edge filters are recommended for normal and longer lenses.