STV have produced a wide range of pest control sytems and weatherproof baits for a wide range of unwanted guests in and around your home or work place. This STV728 sonic mouse and rat repeller provides complete home protection from unwanted rodents. Easy to install, it just plugs in to a standard 3-pin socket and the device is ready and working to protect your home. The STV728 unit has a continuous output of over 100dB at swept frequencies that are too high for people, cats, and dogs to hear. STV units are welfare-friendly and are a deterrent that does no harm to rodents it just moves them on. This is a Value-pack format of 3 plug-in repellers, for all areas around the home or office. PLEASE NOTE: These units are harmful to domestic pets such as hamsters and gerbils.