Been using this for a little while now and I like them. Good peace of mind knowing that you will be notified if the door is opened when you leave. Also good if you have school aged children who now come home after school so you can keep tabs. Initially I thought it was an alarm but these send an alert to your phone through an app and can also send as text. You can alter the noise so that it can make more of a distinct sound. It would be nice if I could preset the sounds to change automatically from the day time to night time so that at night I could get more of a strong alarming sound to wake me, but I haven't found a way to do it. So far they are working very well, and were very easy to set up for me.