A star diagonal is designed for comfortable viewing with astronomical telescopes, the 90 degree angle allows the telescope to be pointed at high angles whilst the eyepiece remains easily accessable. The 1.25" diagonal simply pushes in the standard focuser of any refractor or catadioptric telescope that accepts 1.25" accessories. For terrestrial or daytime views an erecting 45 degree diagonal is recommended.
Please note diagonals are not suitable for Newtonian reflectors.
