This Pro Ii 2-In-1 Circular Polarizer + Variable Neutral Density Filter From Haida Combines A Solid Variable Neutral Density Filter With A Circular Polarizer. It Can Rotate Adjustment Neutral Density Filter Darkens The Entire Image Area To Easily Photograph With A Longer Shutter Speed For Added Blur Or To Convey More Movement. Circular Polarizers Are Ideal For Use With Digital Cameras And Autofocus Lenses Clears Up Haze In Distant Landscapes And Provides More Saturated Vivid Colors.Strongest Effect When Used At A 90