Zelers Upgrade Rechargeable Mini bark Control Device Outdoor Anti-snoring ultrasonic Dog Skin Control Sonic bark Vacuum Cleaner Muffler Stop bark bark Stop Repeller 100% safe, humane and professional way to train your dog to stop barking For dogs of any size - uses high-frequency sound that works to reduce excessive bark of dogs within hearing range; for dogs 6 months and older up to 25 foot range Designed for easy Hanging or mounting on a tree, wall or fence post to keep your own dog or your neighbors dog from barking Contain sensitive microphone isolates and picks up barking up to 50 feet away to stop barking both outdoors and indoors (recommended starting mode for indoors is level 1, increase if needed). note: does not work on Deaf or hearing Impaired dogs. With a green and sustainable charging method, you can work continuously for one month or more in one hour of charging.