I was skeptical at first, but wow! Our Chihuahua mix, Bella, used to bark at EVERYTHING—delivery trucks, mail carriers, even the wind. The ultrasonic sound (which humans can’t hear) immediately gets her attention without stressing her out. After two weeks, she only barks when absolutely necessary. It’s way gentler than those old-school shock collars. If you care about your dog’s well-being and your peace of mind, this is the way to go.