The Orion 1.25" Dielectric Mirror Star Diagonal is an ideal choice for refractor and Cassegrain telescope users who wish to obtain the brightest views possible of the many wonders of the night sky. This high-quality mirror diagonal features sophisticated, lab-tested dielectric coatings that boast an astounding 99% reflectivity. With such high reflectivity, your views of starry skies will be bright, detailed, and full of contrast. Dielectric mirror coatings are more durable than enhanced aluminum coatings, so you'll enjoy years of exceptional performance without degradation.
The machined and anodized aluminum diagonal housing features machine-threaded internal baffles to ensure high-contrast performance and eliminate pesky internal reflections and glare. A non-marring compression ring collar is built-in to safely secure any inserted 1.25" telescope eyepiece without scratches. The diagonal's 1.25" nosepiece barrel is conveniently threaded to accept like-sized filters so you can swap between different telescope eyepieces easily without having to detach and re-attach the filter onto each eyepiece you use. Protective caps are included to keep the diagonal free of dust when not in use.
This diagonal requires approximately 9cm inward focus travel relative to an eyepiece's focus position without the diagonal. Diagonals are not recommended for use with Newtonian reflector telescopes.