VIOFO CPL Filter Anti-Glare Circular Polarizing Lens For A229/T130/A139/A139 PRO/WM1 The CPL (Circular Polarizing Lens) is suitable for the front camera lens. Protect the camera lens from fingerprints, 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 and videos more beautiful. It can be used during day time and at night. Viofo CPL is pre-calibrated in Factory, you just need to match the white line on the CPL with the white line on the camera lens for better performance. - Length 7 cm, width 7 cm, height 3 cm, weight 0.5grams