1.Effective Barking Deterrent This ultrasonic dog whistle serves as an antibarking device, successfully controlling your pet's excessive barking behavior and creating a quieter environment for you. 2.Unique Dual Head Design Featuring a double head and double speaker for a wider coverage, this training device ensures effective training and improved behavior for your pet. 3.Humane Our ultrasonic dog barking deterrent is a noninvasive and humane way to train your dogs. It doesn't cause any harm or discomfort to your pet, ensuring a training method. 4. Our device is designed for simplicity and convenience. Just blow on the whistle to produce ultrasonic tones that will capture your pet's attention and stop them from barking. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.