2-in-1 Functionality : A versatile device combining ultrasonic dog bark control and dog training features. Not only effective stop dog barking,Chewer, Digger, Biter,Chaser,but also fast foster good behavior in your pet. Three Effective Frequency: This dog barking control devices come with three effective frequency modes: fixed frequency , variable frequency, irregular frequency. By switching the frequency mode, prevent the dog from getting used to the ultrasonic waves with a fixed frequency and no longer respond. 100% Safe and Harmless: The frequency received by human ears is within the range of 20HZ-20KHZ, and the frequency received by dogs is within the range of 15HZ-120KHZ. The frequency of our products is 20KHZ-25KHZ, which is 100% harmless to humans and dogs. We advocate gentle and efficient ways to let dogs achieve the training effect we want. It more effective and safety than a dog training clickers,whistle for dogs, and dog bark collar. Fast USB Charging & Long Bettery Life: This anti bark device for dogs with a Type-c port data cable, charging is convenient and fast. It only needs to be charged for 1.5h, and it can last for 30 days! The small anti dog barking deterrent size is 4.92 x 1.18 inches, weight:0.19lb. It's super convenient for you to carry anywhere and easy to use Outdoor & Indoor. LED Flashlight With Multi Settings: The dog barking deterrent devices designed with LED lighting, you can easily use the product at night or in dimly lit environments. Long pressing the light button also has a high-frequency strobe buzzer alarm function that flashes 10 times per second, which can act as a deterrent or SOS.