Alstar 1.25" 90-Degree Diagonal Mirror

Wide 90 degree angle You can view correct image from refractor telescope stand and just look down with a comfortable angle Protective coating on the mirror to ensure a long life metal barrel for secure seating in the focuser More comfortable viewing orientation as you observe from above filter thread for any 125 inch filter Accepts standard 125 inch eyepieces Useful for refractor and Cassegrain telescopes not recommended for reflectors 125 inch 90 degree mirror star diagonal for any telescope with 125 inch connector not suitable for Newtonians