Battery Operated Sonic Rat and Mouse Repeller Battery operated ultrasonic rat and mouse repeller inaudible to the human ear. Ideal for homes, garages, loft spaces, outbuildings, sheds and greenhouses.Very easy to install and totally safe, will not affect other pets or wildlife (except rodents) or humans. Of course, as with all methods involving animal behaviour, we can"t guarantee effectiveness in every situation, however, our own experience and the feedback we get from customers suggests that this device is effective in almost all situations. Eliminates the need for poisons and traps.How does it work?Emits an ultrasonic signal every 8 seconds to protect an unobstructed area of upto 2500sqft.Takes one 9V battery (PP3), (not supplied). The battery should last 4 to 6 months with continuous use.Dimensions: 4.3" x 1" ** Must be used indoors only **