Cheap is not good!

Appearance: You see quite well from only one has the vague feeling one had the these rings already in other hands ...

Processing: Once you have the 3 rings apart, you realize: There's all Black plastic abrasion / plastic residues -> blow the rings firstonce, otherwise you have the stuff in your camera.

Handling: I got it just did not go my lenses on the 31mm ring set to, at first I thought that my objective has any problems until I got the idea to put the 13mm ring to the 31mm ring -> not possible! Obviously, something bent in the ring I broke do not know. 13mm ring to the camera lens on it -> matches. Try to shoot first photo -> Error! Failed to connect to Lens. Interim results: 2 of 3 rings are defective. The 21mm Ring fit then and I was able to rule out that had my camera or my lens faulty one.

But not 2 rings are defective sense of the matter, I have everything together sent back to Amazon. I had all the time had the feeling that the rings are sent someone back itself (according to the motto is some already take)

Conclusion: I'm going to order now significantly more expensive extension tubes have the hopefully not so extreme problems.

Let yourselves from the reviews not teuschen that stuff belongs in the recycling and go anywhere else.