PepeMama Ultrasonic Dog Bark Controller Device in Birdhouse Shape Stop Dog Barking Uses ultrasonic technology to stop barks 50 feet away both outdoors. 4-Levels of Operation (test, low, medium, and high, with LED battery power level indicator) Safe and humane method of bark control, suitable for all breeds and sizes of dogs Uses 9 Volt battery (NOT included). Average battery life is 2 months, depending on how often the dog barks Pre-assembled, easy set-up, requires low maintenance, and weatherproof (but avoid exposing to very cold or very hot temperatures).