Functioning, but just not perfect

Have 25 years ago macrophotography operated with a double set of extension tubes. After a longer "Macro Pause" and advanced technology I wanted to start again. So I bought the intermediate rings described here, knowing full well that there are no "originals".
You do not just a stable impression, the color markings are - as already described in other reviews - accurate even not really. But they work - mostly.
I have tested with three lenses:
1. Canon EF 40 STM ...
Works seamlessly in all ring variations. Data transmission from the lens without defects.
2. Canon EF-S 18-55 IS II
Works seamlessly in all ring variations. Data transmission from the lens without defects.
Through the lens weight, I got something to feel, everything would fall apart. But happened in any Kamerapostion.
3. Canon EF-S 18-135 STM
In this lens I thought from the outset permanently hand below or hung up. After I had a ring attached to the LED front lens, my confidence was moving towards "zero". But the intermediate rings held in all the camera positions. However, at about 10% failed the photos with all three intermediate rings the data transmission from the lens and the camera told me to time brush contacts. After switching off and on the camera, we went mostly more easily. However, I could not build on a specific camera position this error. They also occurred only with this lens.

General for macro photography, I would like to mention that my "old" macro sled still works perfectly with the new technology and I recommend everyone to use a. In conjunction with tripod, wire or remote triggering, and possibly additional light can do small things really big.

Conclusion:
- Lack of stability appearance
- Data transmission failures with a heavier lens, which I could find no real cause
- Otherwise they function exactly as intermediate rings are to function and I knew it from my old SLR System
- I'll keep them so.

If at any time but still fall apart and let fall my lens on motive, I report to. ;-)