I had read the reviews posted before I purchased the product. Many very good and a couple not so good. I want to add, THIS HAS BEEN A GREAT PRODUCT AND EASY TO SET-UP. It is important to read the instructions in order to make it work. I think the reason why a couple people did not get the product to work properly out of the box is, the sensors MUST be sinked to the monitor station. The instructions show you very quickly how to do this. I had each sensor set and in place within 1 minute.