Runshuangyu 6Pcs 4x4 Full & Graduated Neutral Density Filter, ND2 ND4 ND8, Grad ND Filters with Bag for Swing Away Matte Box Holder Set of 6

This graduated/full ND filter is ideal for reducing bright light in large aperture situations when a narrow depth is field is needed. Allows for slower shutter speeds when blurring or showing of movement is desired. Allows balancing of exposure to highlight a key subject. Lets you use higher speed films in bright light. A mattebox really makes it easy to transition between different lenses when your camera is sitting on the rig. Assuming that each lens has a different lens cap diameter - you would have to have ND filters or other filters to fit each lens. But if you use a mattebox you can just simply pull out the mattebox filter holder and pop in this 4" x 4" filter for all size lens. It would save time for you and will be much convenient for your shooting.