ULTRAWIDE 6mm, diameter 31.8mm (1 1/4"). The UltraWide series by SkyWatcher includes wide-angle eyepieces with multiple coatings and large eye relief. The eyepieces offer a generous 66° apparent field of view, allowing the observation of many objects at a glance. They provide sharp images across the entire field of view. They feature rubber eyecups for comfortable viewing and blocking stray external light. They are ideal lenses for telescopes with a short focal length.