It helped me a lot in macro photography.
I have 3 lenses, the classic 18-55 from Nikon, the 70-300 from Tamron, and my favorite Nikkor 40mm f/2.8G which is a true macro lens.
I wanted to be able to get even closer to certain subjects.
So, I bought these tubes.
Positives:
They have electronic contacts, so everything works perfectly and all the information is transmitted correctly.
They are extremely lightweight.
We have several options from 12-20-36mm that we can use however we want, so it doesn't matter if we use them from 36mm-20-12 or any other combination, they will work properly both individually and combined.
For me, the 12mm worked perfectly. If I had all 3 together, I could get so close that it almost touches the lens glass.

Negatives:
This only happens with the 40mm macro lens, for some reason it attaches and detaches very difficultly, it requires a lot of force and it scares me a little.
With the other lenses, everything is fine, so for some reason, it only struggles with this one.
Of course, if I do it carefully, everything is fine, it just bothers me a little.
For some reason, when I use all 3 together, the photo shows some strange blurriness when using flash, which is very important to me in macro photography since I have a custom flash diffuser.
This also doesn't happen when I only have one tube attached. I can't understand the reason, maybe something is happening with the light since the tubes are empty and don't have any glass.

These are the general points I wrote as much as I could to help others who may have the same issue. If anyone knows the solution to any of my problems, please write to me in the comments below.
Happy shopping.