Features: This Anti Bark Device will trigger after more than three times barking, effectively filter out some false triggering cause by environmental noise or dog occasionally bark. Design by sound control and fitted on the wall, easy to install. Come with a rotary wall holder, makes the device can rotate 360 degrees freely. Human cannot hear the ultrasonic, NO harm to human and dog, safe to use. Note: the device's work performance will be affected by environmental noise, work distance and the volume of dog's bark. Package: 1*Anti bark device 1*Power adapter, US/UK/EU Plug 1*Mounted holder 1*Accessories set 1*User manual Specification: Type:Anti Bark Device Material:ABS Quantity:1pcs Item Color:As shown Power Supply:DC 8.4V,500mA PowerAdapter Input Voltage:AC 100V~240V Size:7*13*5cm / 2.8*5.1*2" Note: Do not install in damp, leaking sunlight and easy to encounter a place. If there is loud and lasted noise around, highly suggest that you had better not use this product, the noise environment will affect this product s using life. How to use it: Place the item 1~2 meters far away from the kennel, note keeping from the rain and humidity, assuring people cannot 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.