This Rentokil Ultrasonic Repeller is for the control of garden animal pests including cats, dogs, foxes, squirrels and other small animals. It operates day and night in all weather. Inaudible to humans, this deterrent has a detection range of 10 metres. It is weatherproof, easy to set up and to use. Part of Rentokil's safer range, this ultrasonic repeller is poison free. Takes 1 x 9 volt battery. How To Use: Very simple to use, just insert the 9V alkaline battery, site the unit where cats and other animal pests have been seen or are causing problems, and turn the unit on. It can be attached to a wall, or use the mounting spike (enclosed) to site it at ground level. Repeated exposure to ultrasound creates an uncomfortable environment for cats and other animal pests, which are deterred from the area in front of the unit.