I have two of these installed on my balconies for 3 years now. Many false alarms, especially in the summer. In order to avoid constant false alarms, it needs to be set at the lowest possible sensitivity. However, it still gives occasional false alarms. At the same time, if someone passes by quickly, it might not even detect them. In the end, I had to install cameras to monitor what's happening. If I knew, I would have installed cameras from the beginning without these specific sensors.
*I don't know if the situation has been fixed in newer batches than the one I have.

The sensors have been placed externally on the balcony of an apartment near the windows. They have been connected to the hub2 and I have no false alarms

Unfortunately, it is not the best for outdoor use, something that Ajax has taken care of with a new range of products, but these also work in conjunction with the new range of hubs. On the other hand, they perform impeccably in indoor spaces.

I am not referring to construction quality. Second day of use, nice simple alarm but far from the curtains it detects an outdoor cat that theoretically it shouldn't catch, as the manufacturer says, moving flowers and curtains. In other words, it doesn't work for a house where these things may be happening all day. Bad choice! Better to have contact on every window and an indoor detector in every room instead of external curtains