Use the iOptron 90° Dielectric Star Diagonal to place your head in a comfortable viewing position when your refractor or catadioptric optical tube assembly (OTA) is aimed at or near the zenith. Built with a dielectric hard-coated BK-7 glass mirror, the diagonal transmits more than 99% of the incoming light to ensure clear and bright high-contrast images while maintaining maximum resolution.

Designed to be lightweight and durable, the diagonal features an aluminum housing with a black anodized finish. The 1.25" barrel and eyepiece holder makes it compatible with the most popular size focusers, drawtubes, and accessories; and the brass compression ring in the eyepiece holder ensures your eyepieces won't get marked or marred when locked into place. An internal integrated safety stop in the eyepiece holder protects the mirror and ensures a long life.