Deter your own dog, or other dogs, from barking. Designed to hang or mount on a tree, wall or fence post. Safe and effective for all sizes and breeds of dog. Detects the sound of barking up to 15m away and uses ultrasonic sound to deter nuisance barking. Durable and weatherproof. Not suitable for dogs under 6 months of age. Manufacturer's guarantee of 2 years.