The female part where the American side goes in does not fit properly and securely, resulting in it constantly coming out.

I thought from another comment that I was buying something of better quality but I didn't... I paid for nothing and the shipping. First of all, the product I received is different from the one in the photo. It doesn't have any letters on its plastic and of course it doesn't say 17110. In one of the two that I received, the connection of the male pole with the inner metal is loose and it wasn't done properly, causing sparks if I turned the pole!
Also, the employee who packaged them had the idea to put the two adapters in a row to save space. So, the female plug became completely crooked, since the American male plug has a rectangular cross-section and the European one is round.
Luckily, it has a screw to open the plastic and someone can tighten the female part again or put it in its place.
Typically, if someone pulls their device without holding the adapter, the adapter will stay in the socket, as almost everyone does. Maybe I'll glue it onto the device with hot glue. If I could, I would change the American plug and wouldn't buy an adapter.
Also, the male part doesn't have a few millimeters of plastic insulation, but it's all metal.
The metal seems to be of good quality and that it won't rust.

Very good quality, sturdy plastic, not like those you buy from abroad, it is much more qualitative and sits much better on a power strip or socket. It serves its purpose perfectly. It has never damaged any of my devices.