Ikan Nano IR ND 0.3 4x4 NiSi Nano Infrared Neutral Density 0.3 Filter - 4 x 4 (Black) 1 Stop Infrared Neutral Density Filter 4 mm thick optical glass with precision cut, grinding, and polishing Ultra low color shifting with anti-reflective coating Water proof, scratch, and oil resistant Optimized for shooting raw 6K digital images