4 Humanized Training Modes: Petsuper dog shock collars come with 4 working modes and 7 Adjustable Sensitivities. 4 working modes: beep, vibration, beep+vibration, beep+vibration+shock, provide the most suitable training method for your dog's barking. The 1-7 adjustable sensitivity lets you find the most effective way to curb your dog's barking without causing them stress or pain