Easily correct upside down and left-right reversed image: Allow you view things during daytime in correct position Standard 1.25 inch diameter: Fit for 1.25 inch eyepiece and telescope focuser Designed for: Work with Refractor and catadioptric telescopes,not for reflector telescope Wide 45 degree angle: You can view correct image from refractor telescope stand and just look down with a comfortable angle. Super easy to use: Just insert into 1.25 inch telescope at the silver end,the other end fix 1.25 inch eyepiece by the screw. With dust cover: Always keep your lens clear,prolong life. Material:plastic colour:black Package Contents: 4 * 45-Degree Diagonal Adapter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.