NiSi Filter IP-A for iPhone True Color V-ND 1-5 Stop The transition of density occurs smoothly, which allows the photographer or videographer to adjust exposure length to the exact amount required for a given scene. For easier, repeatable control over density settings, the front ring is visually marked with numbers representing the different stop value The Variable ND offers True Color that avoids color shift seen in other Variable filters. The NiSi True Color ND-VARIO Pro Nano 1-5stops is made from high-definition optical glass for the best resolution and quality. The glass is coated using the NiSi Nano coating, providing a waterproof, oil-proof and anti-reflective coating to avoid ghosting and reflections. To install NiSi IP-A circular filters align the circular filter bayonet to three installation positions. Ensure that the outer bayonet of the filter aligns with the IP-A holder slot and turn clockwise to tighten. If multiple filters need to be installed, align the three bayonets on the second round filter with the three holes on the filter clip slot fixed on the IP-A holder. Ensure that the outer bayonets of the filter are completely aligned with the round filter clip slot, then turn clockwise to tighten. Compatible with the NiSi IP-A Filter Holder for iPhone (Sold Separately) Variable neutral density filter offering greater control over exposure settings, allows reduce shutter speeds and wider apertures True Color result that avoids color shift seen in other Variable filters Reduces exposure by 1 to 5 Stops Exposure range-control filter ring with hard stops at each end No “X”-Effect High Definition optical glass Nano Coating, Waterproof and Anti-Reflective Coating