The test with me through a security door outside and inside door, straight corridor distance approximately 10m, nothing arrived,
what could possibly can be remedied by a change in frequency. But did not have time to test it.
Conclusion: This part works if the distance through walls is quite weak, habs just placed further forward.
For the money, better than no bell ^^
It can also be used by laymen into operation immediately, because the function is also given without Voreistellung.
A minus point for the Polish manual.
A minus because of the weak coverage through walls (I live just in a house and not in the open field xD)