I start by saying that... now that I got it, saw it, touched it, and used it for 2 days already, and for almost €6 that it cost me in total... well... it's good. But if I had to pay more than €10 for it, I would think about it much more, and if it had to be more than €15, I simply wouldn't buy it.

From where I got it (by visiting the store), they gave it to me "bare", I mean without its box. I say this because that's how it is shown in the product photos, with some packaging box. However, that's not the issue because it would go straight to recycling as a box, it wouldn't serve any purpose, so maybe it's better this way (although, the die-hard unboxers lose part of their excitement like this :-p). It was simply inside its own black cloth case.

As soon as I saw it and held it in my hands, I immediately understood and justified all those who have already commented on how small it is because it is indeed very small, borderline. However, it definitely wouldn't be suitable (not on its own) for people with even slightly wide hips. Here I should mention (just to complete the picture of my judgment from my personal use) that I am a man, 1.70 meters tall, 80 kilograms (but somewhat fit and with a narrow waist), and 56 years old.
The purpose of use was to put it on a desk chair in my house (as I spend many hours there every day due to my work). Seeing it, I thought I would have better chances if I put two of them together (one on top of the other), so I directly bought 2 of them and put them that way.

In practice now, although it doesn't look impressive (not even the seat), I can say that they do the job!!! At least for me, they seemed to have a role after all. However, the equation should also include:
a) My physical dimensions (and my weight).
b) The fact that I put two (2) of these cushions together (one on top of the other).
c) I put them on an office chair that already has its own cushion on the seat (which, however, is relatively shallow, sagging, and now it remains for the person sitting on it to feel this hard level of the seat if they don't reinforce it with an additional cushion).
In short, I can say that, for my case, they have been helpful so far!

Additionally, I should mention that the feeling when sitting on them is somewhat like sitting on those... cardboard "egg cartons"! I know that what I wrote sounds a bit funny, but that's how it is. At first, you feel something relatively hard like a surface (and somewhat perforated), but it almost immediately gives way as much as you sit on something that, while soft, is also somewhat hard. It gives you this intermediate surface that, while not as soft as a pillow, is definitely better than not having it there at all. It has a sense of "plasticity" in the way it absorbs the weight of the body, but it doesn't remain depressed when you get up from it (the person who was sitting on it).

The cover of it is also good. It doesn't fit "too tightly" on the cushion, it has enough air in its application (but not excessive), which is good for the process of taking it off or putting it on. One side of the cover is plain, while the other has a density of elastic and very small "beads" that help with the non-slip surface it should have, especially when the cushion is placed on smooth surfaces.

Of course, I still don't know what durability it will have overall, either the pillow itself, or its cover, or the zipper of the cover, etc. Certainly, its durability is also related to its usage. However, no matter what, for only €6, I don't think there will be a problem even if it breaks over time.

Overall then... small but cheap, it doesn't catch the eye but it gets the job done.