A high-powered eyepiece, this unit features a four-element premium symmetrical Plössl optical design. Features include blackened lens edges to minimize internal reflection and maximize contrast and multi-layer coating group on each lens surface to maximize light transmission and contrast. Each Omni goes through a two-step anodizing process to prevent reflection from the top eyepiece barrel, unlike most other manufactures who use reflective surfaces. Threaded barrels accept 1 1/4" Celestron thread-in filters. Recommended for ages 13 and up.