For Digital Imaging. Propriety Multi-Coating with Water Shedding Layer, works like a Lotus Leaf. Highest Quality Scratch Resistant hard Multi-Coating to prevent Abrasions and the effects of mosture, while providing the highest of Light Transmission necessary for High Resolution Imaging. Hgh Tech Hard Multi-Coating makes it possible use Thin 1.4mm Glass versus the competitors 2.0mm. Glass, Coating and Brass Rings are all RoHS Compliant. Edge Sealed Polarizers are much less Likely to Delaminate. Matte Black Carbon Paint used for Edge Coating reduces Internal Reflection. CNC Precision Brass Rings. Slim Filter Mounts. Easy to Clean. Thinner Mount allows use of filter with Wider Lenses. Digital requires not only HR Optical Glass, but also a Flat Seating Serface. The use of Brass helps to ensure Optical Flatness. High Tech Fluorine Anodized Finish is Scratch Reistant. Professional Quality Satin Smooth Finish. Sufficient amount of threads ensures Lens Cap attachment. 2.7mm Threads versus the Competitors 2.0mm. Size: 82mm.