[Auto Anti Dog Barking Device]: Our anti barking device provide a safe and effective solution for stop dog barking. The stop dog barking device can effectively train your dogs to stop unwanted behaviors such as barking, fighting, digging, eating unsafefood, fighting, etc [Works On All Size Dogs]: Work on many sizes of dogs(except dogs under six months or over 8 years and aggressive dogs). Push the Button, and the Barking Controller start to work, effective range is 9 meters. (30ft), All dogs within the scope can hearultrasonic and make actions [3 Modes Anti Barking Device]: 1st Mode: 15KHZ-30KHZ for large and naughty dog; 2nd Mode: 20KHZ for docile dog; 3rd Mode: for small dog. Please do not forget to change the frequency level every 7-10 days. Tips: the device should be replaced in quiet surroundings,and far away from source transmitter equipments like TV, speakers, doorbells for better effect. [Lightweight and Portable]: This dog Barking Stop device is Small and lightweight and Fit perfectly in your pocket, with a wrist strap, designed to be convenient to carry around with you.