Exclusive True Colour Coating: Prevents The Yellow Tint That Is Common With Other Brand Filters And Ensures Absolutely Neutral Colour Rendering So That No Colour Distortions Occur No ''X'' Effect: Provides 5 Fixed Aperture Levels (Nd0.3-Nd1.5) And Allows Gradual Rotation Of The Filter Without The Dreaded ''X'' Effect Multi-Nano Coatings: Up To 20-Layer Anti-Reflective Coatings For Low Reflections Water And Oil Resistant Coating On Both Sides No Vignetting: Larger Front Thread To Avoid Vignetting On 16Mm Lenses With A Filter Frame That Has A Matte Black Interior To Effectively Absorb Stray Light And Reduce Glare Knurled Aluminium Frame: The Knurled Edges Of The Lightweight Precision-Machined Aluminium Frame Of The Nisi Variable Nd Filter Allow Better Grip As Well As Easy Assembly And Disassembly