The CPL filter is used for VIOFO A119MINI2/ A129 Duo / A129 Pro Duo / A129 Plus Duo / A119 V3 / A119 dash camera, suitable for A129 Duo both front and rear lenses.Protect camera lens from finger prints, scratches and dirt destroying.Reduce reflections and glare from glass, metals or shiny surfaces that would damage image quality, this works in the same way as polarized sunglasses.Make colors more saturated Why need CPL filter for camera lens? 1.Protection for the front lens element It protects the front lens element from finger prints, scratches and dirt destroying. 2. Cut off reflections and glare It cuts off reflections and glare from glass, metals or shiny surfaces that would damage image quality, this works in the same way as polarized sunglasses. 3. Make colors more saturated It cuts reflections from surfaces like leaves, grass or walls, making colors appear saturated, and shadows appear blacker. Track Page Views WithAuctiva's Counter