Celestron 1.25" Star Diagonal, Black (94115-A) Fits telescopes with 1.25 focusers or visual back, 90 Degree viewing angle, best for observing objects overhead Accepts standard 1.25 eyepieces, Barlow lenses, and other Accessories with a 1.25 insert barrel PLEASE note that a 90 diagonal will display images that are right side up, but left to right orientation will be reversed.