Olivon 2″ Mirror Star Diagonal. Fully Multi-Coated 2″ 90° diagonal with 1.25″ adapter included. Lightweight, all aluminum construction. Uses 99% Reflective Dielectric coatings. Premium grade, thick, precision, optical flat mirror-based diagonal for all 2″ and 1.25″ focusers and eyepieces. The Olivon 2″ 90° Mirror Star Diagonal utilizes a non-marring compression ring fitting to protect your eyepieces from scratching.