The 20mm medium power Omni eyepiece is a 4 -element premium symmetrical Plössl optical design. Features include blackened lens edges to minimize internal reflection and maximize contrast, multi-layer coating group on each lens surface to maximize light transmission and contrast, and 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.
Focal Length :20 mm (0.79 in)
Eye Relief : 20 mm (0.79 in)
Angular Field of View : 52 °