Meade 07210 No.932 45-Degree Erecting Image Prism Telescope Eyepiece, 1.25-Inch (Black)
All 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.