◆UPGRADED TECH Stop excessive, noisy dog barking by emitting an ultrasonic sound to silence the dog. More effective than old version deterrents and waterproof. ◆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. ◆100% SAFE -- Trusted by dog trainer & veterinarians. No electric shock, no liquid propellant is used, and most humane and used widely way to keep your own dog or your neighbors dog from barking. ◆Operates 9-Volt batteries (not included) and will last up to 6 months depending on use. ◆MINI DESIGN The New Bark Controller come with a well-designed mini shape. Designed for easy hanging/mounting on a tree, wall or fence post to stop any dogs barking (within range)..