Sturdy, hard plastic, but... After 2-3 months of use (once a week), the plastic parts that attach to the stroller have worn out, they don't close properly, and they open in the middle of the walk... It needs some fixing now

It is fine for a walk, not for going up and down sidewalks, stairs, etc. For Greek standards, it is probably difficult to use extensively.
It is also somewhat difficult for a mother to use because it pushes the weight of both the stroller and the baby, but also a large part of the weight of the older child.
The older child enjoys riding it, sees it as a bicycle. However, one must be careful to see if it is compatible with the stroller or not.