something i made and wanted to share with you people. i made it a while ago but didnt have time to post it. its a simple concept but its easier said than done. it hase parallax error ( when you look at an angle the red dot moves instead of staying on target) it can be fixed by putting a concave shaped clear plastic piece in the place shown on the diagram but i did not have anything like that so i just used a flat piece of plastic.
i hope you like it.