3 Effective Training Modes & 5 Sensitivity Levels: Sound, Sound + Vibration, Sound + Static Shock and Sound + Vibration + Static Shock, and each mode has 5 sensitivity levels. The most effective mode can be chosen to train the dog, according to its nature and behavior. Automatic Protection System: If the collar is triggered more than 6 times in 1 minute, it will enter the protection mode, which will deactivate it for 1 minute to ensure the safety of the dog. This mode is to protect your dog and give it time to calm down. Intelligent Bark Detection Chip: The built-in trigger sensor This collar will detect all noises, then filter out only barking to trigger (barking frequencies: 1000-2000kHZ, 80-90db). The collar will only activate when your dog barks, which will allow you to train him properly. Rechargeable and Waterproof: The built-in rechargeable lithium battery is large capacity, and only takes 2 hours to be fully charged, and this offers up to 15 days of use. Charging is done via a