Ultra anti-bark device detect barks from 16 ft away. Once detected, it will automatically emit high-pitch sounds only dogs can hear. Once the barking stops, so will the sound. Multiple functionality includes 2 sensitivity levels. Great for training purposes with all breed of dogs 6 months and up! This is a necessity for foster pet parents, new pet owners and those with vocal dogs especially for people who live in apartments. Easy installation and battery operated. Requires a 9 Volt Battery (not included). Easy installation. Includes hardware for wall mount. 9 Volt Battery (not included).