Bark Control Birdhouse: Humanely Stop Nuisance Dog Barking Outdoors Detects Barking Up To 50ft Away, Ultrasound Travels Up To 200ft 4 Correction Settings Including Test Mode Safe & Effective Bark Cessation For All Sizes And Breeds Of Dogs Durable and Weatherproof, Powered by 9 Volt Battery Designed For Easy Hanging And Mounting