PRO-GRADE NEUTRAL DENSITY FILTER - Darkens Images to Avoid Washed-Out Look. Provides Ultimate Control Over Exposure, Shutter Speed & Color Integrity While Allowing for Wider Aperture Settings, KEEPS YOUR SUBJECT IN FOCUS - ND 0.9 Provides Powerful Light Filtration & +3 Stops of Neutral Density Per Shot for Superior Results; reduces ISO 1/8, Perfect for Outdoor Photography & Complex Lighting Conditions, PREVENTS OVEREXPOSURE OUTDOORS - Limits Light Passage Through the Lens to Ensure Optimal Focus & Depth-of-Field Control for Wide Landscapes; Subject Stays Sharp While Background Subtly Blurs, MINIMAL EFFECT ON OPTICAL QUALITY - Unlike Inferior Filters, Ours Allows You to Balance Brightness & Capture Movement Without Affecting Color or Optical Detail; Double-Threaded for Easy Filter Stacking, COMPATIBLE WITH ALL 55MM LENSES - To Ensure Perfect Fit, True Color, Optimal Saturation & Zero Detail Loss, Verify Lens Thread Size Based on "55" Marking on Lens Barrel or Underneath Lens Cap