I don't think it will stop anyone, it may just delay them for a few seconds. The bar itself is not that sturdy, especially if the threshold is at the height that most are in Greece. I set it to the 2nd-3rd hole from the end, which means that the folding part is fully open. So that's where the "play" is.

Also, if you tighten the bar well - pushing the foot against it - when someone tries to push from the outside, the bar will act as a lever and remove the door from the hinge! But if you don't tighten it well, with the back and forth push of the intruder, the rubber foot will slip. Therefore, it will fall. So you might hear it. Maybe.

Very good, it has adjustable height so that it fits tightly on the door. Very smart product without the need to drill holes in the wall.