The NiSi P1 Prosories ND8 (3 Stop) for Mobile Phones is an ND filter that provides a 3-stop exposure reduction allowing you to photograph with a wider aperture or slower shutter speed than normally required. By slowing your exposure time you are able to control the depth of field and show movement in your images, for example, water flow.  This filter is made from high-quality optical glass (not resin) with nano coating to prevent losing any single bit of detail. Neutral density filters do not affect the coloration of the image and the 0.9 density provides a 3 stop reduction in light from entering the lens. This filter is compatible with the NiSi P1 Prosories Mobile Phone Filter Kit.