Package Includes: 2 pieces of anti barking devices, you can press the button as soon as the dog barks, starting with a safe and effective high noise, the dog will stop barking because it will associate its bark with this unpleasant noise; After a few repetitions, the dog will know that its barking is causing it uncomfortable sensations Humanized Dog Barking Control Device: these dog barking control devices stop dogs from barking by emitting ultrasound, no peculiar odor, non electric shock; Both the automatic acoustic trigger and handheld active emission modes are ideal for training and stopping dogs from barking; The automatic mode is for when the dog is left alone in the home, and the manual mode is for interactive activities Multifunctional Anti Barking Devices: stop barking dog devices combine 3 effective dog training functions, namely lighting, ultrasonic and warning; In manual mode, you can select different functions to train your dog's different behaviors, the lighting function is not only a good bark deterrent, but also can light up the road at night 3 Frequency to Choose: ultrasonic dog bark deterrent with 3 adjustable sensitivity and frequency levels (15-30KHz for large naughty dogs; 20KHz for gentle dogs; 20-30KHz for small dogs), you can choose different waves to easily stop different dogs from barking Rechargeable for Indoor and Outdoor Use: no barking device for dogs is portable size, convenient for dog training outdoors; In automatic mode, the barking control device can be easily placed on a table or shelf; It has a lithium battery with a capacity of 2000 mAh and USB charging port; It only takes 3 hours to fully charge, and it can be applied for 15 days to 4 months, saving you the time to replace the battery