I recently bumped in to Rex while visiting my Aunt. Upon walking up to her front door I heard, what sounded like a big dog, barking. I was shocked, when did my Aunt get a dog? Especially a dog with a bark this big?
Long story short, the dog wasn't real. It was a Rex Plus ED-50 Barking Dog Alarm. The
system is amazingly simple to operate, set the range and the volume. Leave your house or office, and Rex does the rest. I am not exactly sure how the motion detection works because it manages to sense people through walls, doors, and even glass (so it isn't infrared). The range is up to 30-feet and the volume of the dog is pretty good as well.
If I was a burglar I wouldn't bother breaking in to a house with a barking dog. You can get yourself this maintenance free dog for under $80 here.