Well, to not let you be fooled. It is exactly the same spike as the Protecta Ecologic, which costs over 4 euros for 0.5m. And this one here is 0.5m with the only difference that you assemble the spikes yourself very easily and in 2 minutes. You should know that the best spikes are these here. That is, a plastic base and a metal spike. Don't believe that they are inox. None of the spikes are inox. If you wash, for example, the balcony and it gets very wet, the metal parts will start to rust slightly. Don't throw your money away on:
1) completely plastic (plastic base + plastic spikes), because if exposed to a lot of sun, the spikes start to bend.
2) completely metal, supposedly "inox", because they rust very quickly as the rust moves from the base to the spike and vice versa.
*For the outdoor units of air conditioners, e.g., 12,000 BTU, you need a total of 6 spikes. Try to cover the edges as much as possible. Because pigeons will sit in even the smallest gap.
**If pigeons are sitting on the classic outdoor light fixture type "globe," cut a small piece from the base of the spike and glue it with a good silicone.
Of course, a good cleaning is necessary before you glue them anywhere.
These are a few tips from someone who deals with pigeon deterrents.
I hope I helped.