HD GLASS • High Density Sharp Cut UV Glass • Chemically Enhanced Optical Glass is 4x Stronger HD COATING • 8-layer Anti-Reflective Multi-Coating • Water & Oil Repellent, Scratch & Stain Resistant HD FRAME • Wide-Angle Lens Compatible Ultra Thin Frame • Glass Mounted with High Pressure Press Technology A multi-purpose fine-weather filter Absorbs the ultraviolet rays which often makes outdoor photographs hazy and indistinct. A multi-purpose, fine-weather filter for color as well as black and white films. Also serves as a permanent lens protector.