Technical specifications:Size: 13.7 * 5.5 * 2.5cmWeight: 56 gSound pressure: 130 dBMaximum current: 130 MAAvailable distance: within 25cmPower supply by: 9V battery (not included)Package include:1x ultrasonic dog repeller1x instruction manual SAFETY NIGHT WITH DOG REPELLENT 3 in 1: drive dogs / training dogs / illumination. The product uses two ultrasonic transmitters and has a bright LED flashlight that can protect against the vicious dog while you are outdoor at night. PET GOOD BEHAVIOR TRAINER The dog trainer can effectively train your dogs to be obedient and stop some unwanted behaviors, such as barking, digging, chewing and more. Note: dog repeller can't work on dogs with hearing problem, appropriate reward is needed when training. PORTABLE The dog training device is approx. 13.7 * 5.5 * 2.5cm,and fits comfortably into your pocket. It comes with a lanyard, which is convenient for you to carry anywhere you need to, such as jogging or cycling, walking, park and so on. EASY TO OPERATE First open the battery cover and then put 1 piece 9V battery (NOT INCLUDED). There are buttons on the AntiBarking device that represent different functions. For details, please see the picture or the manual. We recommend using this product for dogs above 6 months and under 8 years.