The ideal way to control your neighbor's dog and its nonstop barking! Disguised as an ordinary birdhouse, this weatherproof PetSafe Outdoor Bark Control Ultrasonic Unit detects barking up to 50' away and emits a safe, high-pitched sound (inaudible to humans) that encourages the pooch to cease and desist. Runs on a 9V battery (not included). Manufacturer model #: PBC00-11216. Uses ultrasonic sound to deter unwanted barking Detects barks up to 50 feet with the use of an internal microphone 4 levels of operation: 3 sensitivity levels and a test mode Durable and weatherproof for outdoor use