The Bark Stopper emits a harmless, high-pitched pulse that is inaudible to human ears, but extremely irritating to dogs. Your dog or your neighbor’s dog soon learns to avoid the unwanted behavior! Features two sensitivity settings and works over 6 metres. The water resistant, portable unit can be taken everywhere with you or slide into the wall bracket. Takes one 9volt battery, not included. 12 cm L x 2.5cm D x 3.8cm W. Only suitable for large dogs.