4 Tailored Training Modes: Petsuper dog shock collar offers four customized training modes alongside 7 adjustable sensitivities. 4 working modes: beep, vibration, beep+vibration, beep+vibration+shock, provide the most suitable training method for your dog's barking. We ensure the perfect approach to train your furry friend's barking habit. With sensitivity levels ranging from 1 to 7, you can pinpoint the most effective way to address barking without causing any distress. Suggestion: For large dogs, the shock level should be in the 3-5 range. For small dogs, the shock level should be in the 1-3 range.