Description Standard 0.965 inch diameter fits for 0.965 inch eyepiece and telescope. -astronomical telescope accessories0.965 inch-erecting teliscop mirror 90 Degree Diagonal Adapter Erecting Mirror for Telescope. Designed for refractor and catadioptric telescopes, and not for reflector telescope.-telescope adapter Features - Color: Black. - Size: 8.50X3.50X4.50cm/3.34X1.38X1.77 inch. - Material: Plastic,. - Note: Screw is random style.-diagonal mirror for telescope - Coated lens comes with cover; keep your lenses clean for superior images fidelity.-astronomical telescope mirror - 90 degree diagonal mirror using a refractor telescope and makes the upright; though left and right reversed; not affect astronomical observation.-star diagonal for telescope - More comfortable viewing orientation as you observe from above, thread for any -diagonal adapter0.965 inch. - A diagonal that is angled at 90° helps avoid neck strain when the eyepiece. -Diagonal Mirror - It is manufactured with professional technology to ensure the of the product and can work long time.-astronomical telescope accessory It is manufactured with professional technology to ensure the of the product and can work long time.-spotting mirror adapter Economical 90 degree prisms diagonal for astronomical telescopes and spotting scopes.-telescope accessories 90 degree diagonal mirror using a refractor telescope and makes the images upright; though left and right reversed; not affect astronomical observation.-telescope accessory High quality optical prisms inside rather than a mirror which makes your images clear and compatible with sharp.-telescope diagonal mirror Standard 0.965 inch diameter fits for 0.965 inch eyepiece and telescope. -Diagonal Adapter