Description The dog is our friend,but sometimes its barking is bothering us. Unexpected barking often disturbs neighbors. How do we let our dogs become more gentle? This item is designed by sound control and fitted on the wall. When the dog barks,the sound arouse electric circuit. Ultrasonic wave will emit from the item,it discomforts dog but has no harm to dog. Such ultrasonic wave is heard by the dog only,except human. After several repeated actions,the dog knew the extra sound had been caused by its barking,so a conditional reflex is established. Afterward the dog wound not bark without reason. Description: 100% brand new Humane solve dogs' barking problems Color:As the photos' shown Material:Hard plastic Power Supply:DC 8.4V,500mA Power Adapter Input Voltage: AC 100V~240V Adapter Plug: US Pin How to use it: Place the item 1~2 meters far away from the kennel,note keeping from the rain and humidity,assuring people can not access easily Drilling holes on the wall according to the wall mounting plate,and then insert the plastic base and fitting wall mounting plate using the screws. A power socket is be needed around this item. Adjust the item's direction to the dog activity area. Plug the adapter,turn on the item,completed. Package Included: 1× Wall Mounted Anti Dog Barking No Bark (With Pack) 1× US Pin Charger Adapter 2× Screws 1× Wall Mounting Plate