Stv have produced the well known big cheese brand of pest control systems for a wide range of unwanted guests in and around your home or work place stv717 sonic mouse and rat repeller simply plugs in to any household socket and will give your home protection 247 using ultrasonic sound waves up to 400 square feet 37 square metres it is safe for use around cats and dogs the stv717 is a maintenance free unit you need to do nothing to the unit just plug in and switch on for full protection and it ha