Coating : This PROII CPL-VND 2 in 1 Filter is constructed from optical glass for clarity as well as color fidelity. To prevent internal ghosting and reflections, the glass features eight layers of multi-coating. These coatings also offer greater protection to a filter substrate and help it to stay clean for longer than with uncoated filters.
Frame：Ultra slim aluminum alloy ring ensures durability while allowing the filter to remain lightweight. The thin, aluminum-alloy filter ring minimizes the potential for vignetting, while remaining durable and lightweight.