Model 932 Image Erecting Prism #07210 for ETX-90 and ETX-125. Produces a correctly oriented image and convenient 45 observing angle for terrestrial observations. All ETX-90 and ETX-125 models feature an internal flip mirror to reflect light to the telescopes convenient 90 astronomical observing position. In this position the telescopes image is upright, but mirror reversed from left to right. While this is normal and poses no problem for astronomy, in terrestrial observing a corrected image is highly desirable which is where this useful accessory comes in. For observing wildlife, a home with a view, or other Earthly applications the #932 45 Erecting Prism attaches in seconds and results in an image both right side up and correct left to right as well as a more convenient (for daytime work) 45 observing angle.
Threads to the rear camera port. For all ETX-90 and ETX-125 models. "From the ManufacturerAll ETX models include an internal flat mirror to reflect light to the telescope's 90 degree astronomical observing position; in this position the telescope's image is upright, but reversed. For terrestrial observing the 45 degree Erecting Prism results in a correctly oriented image and a convenient 45 degree observing angle.