ORIGINAL ... Athabasca 82mm HD CPL Filter HD CPL, high definition circular polarizer, is mainly used to eliminate polaring light. Using Japan imported optical glass and top quality Japan polarizing films and with secondary advanced operation, Athabasca HD CPL is certain to achieve super HD effect. Specifications : Materials: Environmentally oxidized aviation aluminum Raw materials: Japan imported optical glass & polarizing films Technology: Advanced HD processed Thickness:5.52mm How to Use: Fix the HD CPL directly to the front lens, rotate the HD CPL and observe the polarized light source through the LCD or viewfinder, until the polarized light weakens or disappears as expected.