Rex Plus II, the electronic watchdog alarm, is designed to deter burglars without a real dog. With its electronic radar eyes, Rex II can detect through thick doors, walls and glass. When it detects movement, it starts to emit the selected sound (dog 1, dog 2, two dogs together, ding, ding dong, chirp, siren 1 or siren 2). The closer an intruder gets, the more frequent the barking becomes. As the intruder backs off, the barking decreases in frequency, stopping completely when movement is out of range. A water-resistant flip top provides easy access to the controls. It plugs in to a standard electrical outlet or uses six C batteries. Its detection range is adjustable up to 26 ft. (range reduced through obstructions), and its detection angle is 150 deg. Setup can be done with voice messages or prompts.