ND filters evenly block the light entering the lens and reaching the camera sensor, without altering the overall color of the frame. The difference between each ND filter lies in its opacity. The adjustable neutral density filter Kent Faith offered by us reduces light from one to 9 stops and is made from high-performance optical glass. It is extremely thin (only 7.3 millimeters) and the glass is supported by CNC machined aluminum. The filter fits all 72mm lenses ("ø 72"), but with step-down rings, you can attach it to any lens. The advantage of a large filter is that you can keep and adapt it to any lens, unlike purchasing a separate filter for each lens.