I have 2 sensors continuously connected for 4 months to an rf bridge alarm at 433Mhz. They are reliable and even though I have them outdoors (one on the outside and top part of a window with insufficient shelter), they work flawlessly and have not given any false alarms. Additionally, every time there was actual movement, they did not fail to detect it. I am very satisfied with what I wanted them for and that is why I will look to purchase 3 more of the same.