I purchased this to make it easier on my brain to use my Orion 90mm StarMax for terrestrial viewing. It did the trick. I try to stick with the reversed image for astronomical viewing but sometimes I'll also use it for celestial viewing if I'm having trouble finding objects at higher magnifications.
Great service from Jacobsdigital, ordered Monday morning, in my hands Tuesday afternoon! This item was ordered to replace an OEM 45º upright image diagonal that was very difficult to use for stargazing high in the sky. I thought the OEM unit was pretty good quality but the Orion, even in the brief period available to me for observing (cloud dodging), was a step up in quality and clarity of image. Recommended.
Very pleased with purchase.