K&F Concept Black Diffusion 1/4 Effect Filter & Variable ND2-ND400 ND Filter 2-in-1 for Camera Lens with 28 Multi-Layer Coatings Informations: Material : Import Japanese AGC glass Frame Thickness: 7.4mm Frame Material: Aluminum-Magnesium Alloy Coatings: 28 Multi-Layer coatings on both sides. ND2-ND400: 1-9 Stops variable , flexible adjust the amount of light enter in lens according scenes needs. Black Diffusion 1/4 : 84% standar transmittance , creats cinematic dream effect for video & images, recommend use it in portrait photography. About this item: * 2-in-1 set Multi-function ND2-400 & Black Mist 1/4 filter, one filter has two functions, it can be used as a light filter or a black mist filter. * Thin frame & large friction The surface of the frame is designed with CNC trapezoidal pattern to ensure a large area of friction when rotating, so you can install/remove the lens and other accessories anytime, anywhere. The frame is made of aviation-grade aluminum, and the 7.4mm thin frame design ensures that there will be no vignetting at both the wide-angle end and the telephoto end. * 28-layer coating & 84% transmittance Top optical glass, the lens adopts double-sided 28-layer anti-reflection coating on both sides, which can effectively reduce filter reflection, and perfectly achieve the 84% transmittance of 1/4 black mist filter standard. The optical glass is finely ground and polished on both sides to ensure the stability of the molecular structure, which does not affect the sharpness on the telephoto lens and ensures high-definition imaging. * 9 f-stops 9 stops infinitely adjustable dimming, quickly adjust the amount of light entering. * Coating and anti-fouling The glass double-sided coating is anti-mildew, waterproof, anti-scratch, anti-oil, even if it is contaminated with water droplets or oil, it can be easily removed. Variable ND & Cinematic Mist Effect 2-in-1 Variable ND2-400 & black diffusion 1/4 effect 2-in-1, provides light reduction and lowered contrast, creates a dream effect of video and photos. 28 Multi-Layer Coated Both glass with nanometer coatings (total 28 layers) waterproof, scratch resistant and dust proof, without negative effect of image quality. Putter Adjustable 1-9 Stops Provides 1-9 stops of light reduction, covering and fitting the daily light reduction need. Type: Black Diffusion 1/4 Effect Filter & Variable ND2-ND400 ND Filter 2-in-1 Guidelines for selecting filter size