Safety Technology International - STI ED-50 Rex Plus Electronic Watchdog Barking Dog Alarm. This electronic watchdog alarm never needs sleep, a walk, food or water; yet is always on duty guarding and protecting. Choose from four settings: continual tranquil sounds of the rainforest, alert sound of an angry and protective watchdog, soothing sounds to alert you of a guest's arrival, and alert sounds of both the angry watchdog and a warning siren. Rex Plus can see through thick doors, walls and glass. Once you plug his cord into any standard 110-VAC electrical outlet, he'll stay on duty around the clock. Place Rex Plus in any location indoors where you would like him to detect and watch him go. When there is any movement detected, Rex Plus will alert you with the sounds you have chosen. The closer the intruder, the more frequent the sounds. Ideal for homes, apartments, mobile homes, RVs, jewelry stores, hotels, public and private buildings of virtually every kind. Limited 90 day warranty. Safety Technology International, Inc. "We protect the things that protect you"