Installation. Now switch your filter in 2-3 seconds with Freewell Quick Swap Magnetic system no more threading. Optical Glass. Made of using the High Definition Premium Optical glass double-side multicoated Zero chromatic aberration (color shift). Function. ND8 (3 f-stops) Neutral Density Filter helps during sunrise/sunset as well as adding motion blur to your videos. Coating. Each side of the glass element is coated with Waterproof, Dustproof, Scratchproof, Oilproof to make sure you are ready for all the adventures.