Mounted within a non-threaded, steel filter ring, this filter is made specifically to fit within a separately available Kase 90mm Magnetic Lens Adapter Ring behind a Kase K9 100mm Filter Holder. Constructed from Schott B270 Superwhite glass for enhanced clarity and color fidelity, each glass surface includes multiple layers of anti-reflection coatings to prevent internal ghosting and reflections. These coatings also offer greater protection to the filter substrate and help it to stay clean for longer than with uncoated filters.