General description 3 in 1 Ultrasonic Anti-Dog Self Defense Device is designed to generate powerful ultrasonic waves that effectively deter dogs. When dogs hear these ultrasonic sounds, they feel uncomfortable and tend to stay away from humans. This device can also assist in dog behavior training by safely stimulating the dog's nervous system, allowing it to accept guidance from its owner. Additionally, it features an infrared light that helps train dogs to stop undesirable behaviors such as barking, digging, and fighting. Technical specifications Type: Ultrasonic dog repeller Power source: 9V battery (not included) Color: Black Usage Open the battery cover and insert a 9V battery to operate. Turn on the switch to activate the ultrasonic waves. Can be used as a flashlight when needed. Portable design makes it convenient for outdoor activities like jogging, walking, or cycling. Other information Not effective for dogs with hearing problems. Not recommended for dogs under 6 months old