1. Adjust the gray scale arbitrarily, adjust it from ND2 to ND4 and then to ND8 until it is adjusted to ND400 2. More stable connection, prevent idling, durable 3. Aviation Grade Aluminum Alloy :Slim ,Durable ,Waterproof 4. Slim Filter Frame :Suitable For Wide Angle Long Focus Lens ,Compliance with EU Environmental Standards for Restricting Hazardous Substances 5. Reduce the Intensity Of Light Without Appreciably Changing Its Color. 6. Easy to Collect and Install |