Ultrasonic Anti Bark Pet Dog Training Collar Control Stop Barking Humane and safe: harmless to your dog, NO electric shock Accuracy: triggered by bark vibration, the ultrasonic sound from the collar reinforces dog's behavior. It will NOT be activated by other dogs' barking. Small sized and light weighted Powered by 2x button batteries (not included);Size: 6.5 x 1.5 x 6.5cm