K&F Concept 46mm Variable ND Filter ND2 - ND400 Adjustable Fader Neutral Density, Ultra Slim Waterproof Multi Coating Optical Glass Lens Filter (Nano-K Series). 【High-end Optical Glass】K&F Concept variable neutral density filter made of high-end optical glass, double-sided multi-layer blue coating is conducive to waterproof and dustproof.
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