The Nikko ND-1000 is a Nano-Coated neutral density filter with a density of 3 stops. Neutral density filters are used to reduce the amount of light entering the lens without affecting the color balance of the image. This allows for slower shutter speeds, wider apertures, or the use of ND filters in bright light conditions. The Nano-Coating technology on the Nikko ND-1000 helps to reduce glare and flare, resulting in clearer, more vivid images. It is compatible with lens threads with a diameter of 77mm.