Although I did not buy the devices via Amazon, but smiles for about half the price at R **, but for little money should be entitled to expect functioning goods. As long as the devices work, they do so reliably. Unfortunately, only very briefly: All four devices have given up the ghost between 6 Studen and 3 months. At least give the devices their demise with a shrill alarm duration known so you do not weigh in false security. On the other hand, as a nocturnal false alarm some also bring a lot of trouble ... Therefore, no purchase recommendation!
