very convenient alternative to a macro lens

I bought this ring for my Canon EOS 400D and am thrilled how well this works.
The ring could be very good bolts on my camera and lens also could be screwed well.
Of course, the camera can not auto focus, but if you have a steady hand, you can make the image very sharp even by the camera moves back and forth, or the focal length of the lens changes.

Even unscrewing has not been a problem.

For this I take photos only as a hobby, this ring is enough for me as a cheap alternative of completely. I can only recommend it.