We are very pleased with the alarm! Luckily, she had not yet prove in an emergency, but since we have often accidentally caused a false alarm (fault of their own, because the plant can not help it), we know that it works just fine. For more alert we have the external siren ordered. The fact that the sensors, external siren, motion detectors are connected wirelessly via radio, etc. with the base station, is super handy. The batteries we had so far only in the external siren switch (through the false alarms!). The call function in alarm works well. The installation is relatively simple, only when attaching the door / window sensors have to be very careful.