1Frame is made of aviationgrade aluminum alloy material, CNC precise processing, surface anodizing treatment, lettering, easy to install and take, made with highdefinition optical glass, durable. 2Using the ND16 filter, you can get more DOF to control the aperture and shutter, bring more exposure methods and create space for photography creation, and effectively prevent overexposure. 3The number behind ND represents the ability of the ND filter to block light. 4Adopting doublesided multilayer nanometer coating technology, waterproof, scratchproof, and oilproof, the surface of the lens forms a protective layer similar to the surface of the leaf, water droplets and oil cannot be absorbed on the surface, and it is easier to cleaning and maintain. 5ND16 filter, suitable for GOPRO HERO9 action camera.1 x ND16 Filter