Are you fed up with your dog barking frantically? The secret to making your dog stop barking without yelling at you! When you have a disobedient, grumpy and disobedient dog, you need sonic bark deterrents that are more practical and safer than collars to train your dog and prevent some of its bad behavior. How does dog barking deterrent devices work? When you encounter your dog trying to attack you, please take out this dog barking deterrent devices. The barking control devices will immediately emit ultrasound to the dog. Dog barking deterrent devices have super bright flashing LEDs and can also let the dog know the source and location of the weapon, so as to understand that you are against it. Face the dog and press the button for a few seconds. Barking control devices will emit strong ultrasonic waves, and the white LED lights in front will flash to chase the dogs away . Specification: Dimensions: 4.13 x 1.77 x 1.57 in Weight:1.9oz Distance: 8sft Notice: 1. Barking control devices use batteries. 2. When the battery voltage is too low, the ultrasonic energy emitted by the product will decrease. At this time, the front flash will dim, indicating that the battery is low and needs to be replaced. Package contains 1 x lanyard 1 x anti barking device 1 x manual