The VOSOV Ultrasonic Dog Bark Deterrent is a 2-in-1 device that offers both training and protection against unwanted barking. With one button, it emits an ultrasound that makes dogs feel the noise and stop bad behavior. The unique round mouth design of the ultrasonic device can better gather the ultrasonic waves, and then transmit them to the dog in a concentrated manner, which effectively reduces the loss and improves the efficacy of the ultrasonic waves.