After a salesman came to my door, I got curious and asked the internet about “door-to-door home security” and found out a tremendous number of items on the subject. I learned enough to be glad that I finally convinced him I was not interested. I was somewhat peeved that I had to tell him so many times that I was not interested. I noticed his car had a Missouri tag. I will not try to repeat everything from the internet but I would recommend you type in “door to door home security” and read as many as you have time for. There is information about equipment companies, sales groups, rating bureaus...