3 Modes Ultrasonic Outdoor Dog Bark Control. The Anti-bark Deterrent has 3 adjustable ultrasonic volume levels: low range, medium range, and high range. Detects and stops dog barking up to 50 feet from the device. Unique and good looking, designed with mounting provisions for easy installation, small & light weight enough to place or hang pretty much anywhere. Solid, Lightweight, Waterproof material allows safe use indoors and outdoors in all weather conditions. 100% Safe Anti-bark Repellent. Emits an ultrasonic sound that distracts your dog to interrupt a constant barking pattern. Harmless and humane way to keep your dog and your neighbor’s dog from barking! Effective on all breeds & all dog sizes.