This 77mm Kase Soft-Edge Graduated ND Filter with Magnetic Ring mounts on the front of your lens to provide you with a soft graduated filter with an adjustable angle. Typically used to help control exposure of the sky, use this 4-stop filter to darken and control exposure in bright areas of the frame while not affecting darker areas, such as the ground, when photographing landscapes. The soft graduation provides a natural-looking transition that does not have a defined transition boundary. The adapter ring allows you to magnetically mount the filter on your lens.