Fangrui Product Details What Is Nd (neutral Density Filter) Also Called Neutral Density Filter, Its Function Is To Reduce The Entry Of Light When Shooting, Neutral Density Filter Plays A Very Important Role In A Good Photo. Ultra-clear Optical Glass - Nd Filter Is Made Of Optical Glass Material, Double-sided Multi-layer Coating, Which Can Enhance Transmittance And Reduce Reflectivity. Low Color Cast, Restore Color, And Improve Image Quality. Mainstream Mobile Phones Can Be Used - 67mm Large Opening, Suitable For More Than Of Models, Without Blocking The Mobile Phone Lens. How To Use Nd Filter On Mobile Phone: 1. Fix The Mobile Phone, Slow Shutter Requires A Longer Exposure Time, It Is Recommended To Use A Tripod 2. Add Nd Filter 3. Open The Camera Professional Mode 4. Reduce The Iso Sensitivity To The Lowest Value 5. Adjust The Shutter Time To The Appropriate Position And Click To Shoot Android: Most Android Phones Have Professional Modes, Which Can Adjust Is0 And Shutter Speed. For Apple: It Is Recommended To Download Th