Please note: This text was taken directly from the manufacturer.
This precision 90-deg star diagonal feature fully coated prisms, delivering superior image fidelity. Features a machined aluminum eyepiece holder and a chrome-plated metal barrel that's threaded for filters. The eyepiece holder has a setscrew for locking the eyepiece securely in place. It produces an image that is right-side up and reversed left to right (therefore, not recommended for terrestrial observing). Diagonals are not recommended for use in reflector telescopes. Fits in 1.25" focusers and accepts 1.25"-diameter eyepieces.
