Welcome to our store Multi-functions: except as a pet training tool, it can also prevent you from dog attacks, suitable for training many kinds of dogs, such as pets, dogs police and shepherds, suitable for outdoor work, travel and security night patrol. Note: May not be effective for big dogs and fierce dogs Ultrasound design: Based on the theory that ultrasound dog trainer can effectively train your dogs to be obedient and stop some unwanted behaviors, such as barking, digging, chewing and more, they are also harmless to humans and pets Easy to use: first open the lid of the battery, then put a 9V battery (not included), the sound is audible only for pets, finally turn on the switch and it can work well, they can also be used as a flashlight if needed. Note: The effective range of this product is 20 feet Portable and convenient: The device size is approx. 13.7*5.5*2.5cm (L*W*H), which is portable and portable, also convenient for you wherever you need, such as jogging or walking, cycling, park, etc. < p>The package includes: 1 ultrasonic dog trainer and 1 user manual; dog trainer color: orange; Note: Dog repellent can work on most dogs, but sometimes not on those giant dogs c