USB Rechargeable: Battery required, just plug it in via USB to charge, very convenient. Ultrasonic Technology: The collar emits ultrasonic waves that are inaudible to humans but can effectively stop barking. Automatic Collar: The collar automatically activates when barking is detected, making it easy to use and effective for training your dog. Vibration Function: The collar also has a vibration function, which can be used as an alternative to ultrasonic. An effective behavior modification tool that can help you train your dog to be less . Easily recharged with a USB cord. It is more , lighter and more comfortable for dogs. Whether your dog is small or large, the adjustable anti-bark collar will fit him well. The collar is waterproof, so you don't have to worry about using it even in rainy days. For some large dogs and dogs with longer hair, it is recommended to trim some hair to ensure the effectiveness of the product. Please make sure you have a good battery before testing. Do not