Handheld Dog Repeller And Trainer, Upgraded 3-in-1 Anti-barking Device_aaSafe night with dog repellent-three in one: dog repellent/training dog/lighting. This product uses two ultrasonic transmitters and comes with a bright LED flashlight, which can protect bad dogs when you are outdoors at night.Pet Good Behavior TrainerThe dog trainer can effectively train your dog to be obedient and stop some unwelcome behaviors, such as barking, digging, chewing, etc. Note: The dog repellent cannot be used on dogs with hearing problems, and proper rewards are required during training.Safe for humans and pets-Ultrasonic handheld dog repellent and trainer devices use physical methods to stimulate dogs. Human hearing range is 20HZ~20KHZ; dog hearing range is 15HZ~120KHZ. The ultrasonic barking control emits an ultrasonic wave of about 35~45HKZ, so it is safe for humans and pets.Portable-Dog training equipment approx. 5.3x1.5x0.8 inches, fits easily into your pocket. Equipped with a lanyard, which is convenient for you to carry to any place you need, such as jogging or cycling, walking, parks, etc.Easy to operate-first open the battery cover, and then insert a 9V battery (not included). There are buttons representing different functions on the anti-barking device. Please see the picture or manual for details. We recommend using this product for dogs over 6 months old and under 8 years old.