Good quality / price anywhere else!

In order to anticipate a: The intermediate rings are made in China with Chinese characters on the packaging.
Yes, they are cheap, but they are, after all, made of anodized aluminum and not plastic. So I admit still 5 stars. Let's face it. What can be for 20, - expect? The fit and not wobble! And they fit and do not wobble.
I use these intermediate rings with my EF 50 II 1.8 (which in itself is a nice, lightweight lens) and had no problems.
Of course, I agree with a previous reviewer that you should not have to use a large, heavy lens. It could be that the lenses are worn, but I want it not also try with my EF-S 17-85 IS USM. I had what it takes and it goes well, but really all I did not dare it.

At the intermediate rings are a very beautiful thing, and I generally recommend using a fixed focal length. The 17-85 I would have to extend to 85 mm to ever be able to focus, with my 50 mm folds without problems.
The lens ring has a small screw that you have to unlock the ring press away from the lens, otherwise you can not get this off. Mir has been chasing it a scare, as I have not got my glass from the ring. Unfortunately Instructions not included.

I would like to briefly explain how to set the shutter of the EOS series, as the intermediate ring interrupts the electrical contact and I did not know beforehand how else to set the aperture.

Setting the Aperture:
- The camera is set to Tv
- Set the desired aperture
- Press the Depth of Field Preview
- Unscrew the lens while holding the Preview button
- Set the lens to the ring
Connect camera with ring -
Make camera on Tv -
- Done!

For 20, - and with a fixed focal length or another (lighter) lens can be very favorable macro photograph.
If you want to have an easier time of buys a genuine Canon intermediate ring. Here, the contacts are connected, but for a ring you pay so well already 70, -.
Who macrophotography suits who buys later usually a decent macro lens. But why once buy an expensive macro when you afterwards notes that you hardly photographed it :-)