With 8-element multi-coated optics, including aspheric lenses, SVBONY SV245 Universal Zoom Eyepiece delivers stunning sharpness, contrast, and color correction across a wide 63° field of view. Parfocal from 8-16mm, it eliminates the need for constant refocusing. It features 18-17mm eye relief and an adjustable rubber eyecup, perfect for glasses or direct use. Compatible with 1.25 inch and 2 inch barrels. SV188P 1.25in diagonal fits telescopes with 1.25in focusers. Accepts standard 1.25” eyepieces, filters, Barlow lenses and other accessories with a 1.25in insert barrel. 90° Viewing Angle. For more comfortable overhead viewing through refractor and Cassegrain type telescopes. 90 degree viewing angle; diagonal reflects the telescope's light path 90 degree to provide a more comfortable viewing angle; best for observing objects overhead, Correct upside down and left right reversed image; the view image is upright; but left and right reversed if use the 90 degrees to your telescope.