The MAS 6414 is a dual-ended permanent marker specifically designed for labeling optical media and other smooth surfaces. It features two different nibs to handle various writing needs, offering a 0.5 mm fine tip for detailed notes and a 1.0 mm broad tip for clearer, bolder headings. Its ink is formulated to be fast-drying and non-smudging, which prevents accidental smears during the archiving process. Because the formula is non-corrosive, you can safely mark CDs, DVDs, and Blu-ray discs without worrying about damaging the reflective surface of the media. This makes it a practical tool for organizing home collections or managing office files on plastic and similar materials.