Alstar 125 45degree Diagonal Prism optical Prism inside rather than a mirror which makes your image clear and sharp

Diagonal Prism Optical Prism inside rather than a mirror which makes your image clear and sharp, 1.25 inch 45 degree mirror star diagonal for any telescope with 1.25 inch connector ;not suitable for Newtonians, More comfortable viewing orientation as you observe from above; filter thread for any 1.25 inch filter;. Accepts standard 1.25 inch eyepieces, This is a great diagonal for daytime terrestrial use and night time astronomy applications for telescopes or spotting scopes, Protective coating on the mirror to ensure a long life; metal barrel; for secure seating in the focuser