18 Layer Nano Multi-Resistance-Coating, Waterproof, Oil Proof, Scratches Resistant Easy to adjust neutral density freely from ND8 to ND800. Rotating it in order to change 2-8 stops. It offers you the freedom the create different neutral density freely. Apply slow shutter speed under strong sunlight exposure, large aperture is available to create depth of field easily In a bright environment to shoot strong dynamic screen, e.g. waterfalls, streams, waves etc. Please note it might cause Vignetting when use with super wide angle lens. E.g.. 20MM lens with full frame camera, but no problem with half frame camera.