Gosky 1.25inch 20mm Illuminated Eyepiece - Illmination Eyepiece for Astronomical Telescope - Long Focal Length - Wide 70-degree Apparent Field-of-view FOV - Adjustable Cross-hair Brightness - Easier to Locate Desirable Targets for Alignment or Guiding - Anti-reflection Coatings for Crisp Views 1.25" 20mm super wide angle eyepiece, wide 70 degree apparent field of view (FOV)-- making it easier to locate desirable targets for alignment or guiding. Steplessly adjust the brightness of the single crosshair reticle - just rotate the switch to put it on, shut it off and adjust the brightness - allowing you to ideally adjust it to the brightness of the guide star Fully multi-coated (all air-to-glass surfaces) with anti-reflection coatings for bright, crisp views. Super sharp, with excellent aberration correction and extremely high resolution 16mm eye relief and folddown rubber eyeguard for comfortable and adjustable viewing Threaded for 1.25" astronomy filters.