Viofo CPL filter for the Viofo A139, A229 and T130 dash cams to protect the lens against harmful radiation and to remove disturbing reflections in the image. The CPL filter works for the dashcam like Polaroid glasses for the eyes. The lens is protected against UV radiation and bright light. Disturbing reflections in the image are also largely removed using this CPL filter. Ideally suited for filming in sunny conditions.