We have Protection One and I have an app on my iPhone so we can set it, unset it, and see if anything happens while we are away. the system is monitored. It is just one level of being safe. The times we've set the thing off by accident, they do call us right away to check on us. And now it is some kind of set up that if someone outside cut the electricity, it would still work. We had a German Shepherd for 13 years and I always felt very safe with him there, although he loved everyone who came in. We never tested him on what he would do if someone strange came without us inviting them!! But just the sight of him would send anyone coming to the door to sell something backing away!!