Very high quality and well-designed. They are not difficult to open and close.
It is worth mentioning that Cyclops is a Greek company. I have noticed that Greek products are usually much higher quality than Chinese ones, even though they don't cost much more.

EDIT 5.7.2023: After so many months of use, I realized another advantage: Due to their shape, they are much easier to clean than many other containers.

Practical. In terms of appearance, it is exactly what I expected and what I saw when the product arrived in my hands. Its positives are that it comes in various sizes, which is very useful. The lids are also extremely durable. On the very negative side, I have some doubts about the quality because the containers leave marks even after cleaning, and they are not easy to remove. It takes a lot of effort to clean them. Overall, personally, they serve me well. All the sizes can be used for storing various foods, desserts, etc.

Wonderful Set with very good material quality!!!
100% Greek company since they are manufactured in Nea Vissa Orestiada!!!