Zomei&reg; Ultra Slim HD 18 Layer Super Multi-Coated SCHOTT Glass PRO MC-CPL Circular Polarizing Polarizer Lens Filter - 49mm Double Thread, 18-Layer super anti-reflection multi-coated with EVERCLEAR 5(WATER REPELLENT / ANTI-OIL / ANTI-DUST / ANTI-SOIL / SCRATCH RESISTANT) Coating Technology to withstand almost any conditions. With only 4.1mm thickness and polarization rate up to 99.9%, this CPL might be the thinnest and the best in the world. Made with no compromise, it still has a rotating ring to set the polarization. Nearly zero distortion when light go through this HD filter. Original SCHOTT Glass from Germany, Compare B+W. All Materials Used in this filter Meet the Requirements of European Union's standards of Environ Ment Protection-ROHS(Restrictions on Hazardous Substances).