I'm surprised to see it works. Anyway, it can detect a GPS magnetic field but has to be close to the device. Wireless connection can also be detected. However, it has to be in close range even with the antenna. The downside is that it also detects mobile signals, which is a false positive. Red light is powerful and can see camera lens reflection. filter isn't much of a use to me, and it is hard to see with it.
The product seems to be good, however, I feel that in order to locate an electronic object, it is necessary to have it very close so that I detected it
Works great, I tested it next to a wifi transmitter component and it was able to detect