Rated as best in their class by Sky and Telescope magazine, the Ultima eyepieces use a 5-element hybrid
optical design. They feature long eye relief and a wide field, and each air-to-glass surface is fully
multicoated to enhance contrast levels. These special eyepieces are computer designed to keep visual
aberrations to an absolute minimum. They virtually eliminate the following aberrations: spherical, color,
field curvature, coma, astigmatism, distortion and spherical distortion of the exit pupil. The inside surfaces
and edges of all lenses are blackened, to keep out reflected light. Outside surfaces are flat black, with
rubber grips for secure handling. Rubber eyecups are included both for comfortable use and to keep out
extraneous light. Threaded barrels accept Celestron 1-1/4" thread-in filters. Lens and barrel caps are
included for safe storage.