EXTRA THIN, EXTRA LIGHT Only 0.8mm Thin Glass, 10g Feather Light Filter Zeta EX uses a specially polished 4 layer thin glass and ultra thin frame combination making it wide-angle lens compatible. Even with being this thin, the Zeta EX still has the front screw on function for attaching a lens cap. The super light weight mechanically benefits certain AF lenses. EXTRA BRIGHT High Transparency Polarizing Film Zeta EX transmits as much as 25% more light through the polarizing film, giving the photographer about 1 stop more light than a standard circular polarizer. EXTRA ANTI-REFLECTIVE ZR ( Zero Reflection ) Super Multi-Coating This innovative coating will not interfere with any color or light transmission. Reflections are eliminated by allowing light to enter the filter at virtually any angle. EXTRA SMOOTH GLASS Nano Glass Technology Our Nano Glass Technology creates an ultra smooth surface from the finest particles of glass, making it stain and scratch resistant without any effect to the image.