The Ultrascopic eyepiece series offers unsurpassed image fidelity. Rather than having a single layer of magnesium fluoride on most lens elements, Ultrascopics are Ultra Multi-Coated, meaning that every air-to-glass lens surface is vacuum coated with multiple anti-reflective layers. There is no higher level of multi-coating. These coatings, coupled with a low-reflection barrel with blackened lens edges, improves both brightness and contrast of faint nebulas and galaxies. These premium 1.25" eyepieces employ 5- or 7-elements using high-refractive-index glass. Each produces a wide 52-deg apparent field of view . Internally threaded for filters.