Nest 9 is an ultrasonic dog bark control device. It emits ultrasound to stimulate the dog, at the same time please with a STOP training gesture. The device can automatically detect barking, has no effect on dogs, and is safe for humans. Its built-in 1500mA battery, fully charged in 5 hours, continuously work for 30 days. You and your families finally take back your peace and quiet, thanks to the new technology. If you want to improve your dog's behavior, you can use the nest 9 device is not suitable for use on dogs with hearing problems. But it can be used to decorate or anti neighbor's dog. It can stand for up to 60 days and be fully charged in 5 hours. If you have any questions, please contact us at info@nest9.com.nz. Product not intended to provide protection against aggressive dogs.