Effectively and humanely stop your dog from barking with the SportDOG Brand® NoBark 6. The vibration of your dog's bark triggers the Vibration Sensor Probe, which then sends a static stimulation through the contact points. The NoBark starts with the lowest level of correction, and gradually increases through 6 levels each time your dog barks within 30 seconds of the previous bark. If your dog doesn't bark again within 30 seconds, it resets itself to the lowest level of correction. Along with each correction, there's also an audible beep. As an added safety feature, the NoBark automatically shut offs for 3 minutes if your dog barks 15 times or more within a 50-second period.