Fangrui Product Details Anti-barking Device: Ultrasonic Dog Trainers Are Great Devices For Dog Training And Barking Control. Ultrasonic Frequency (25khz) Has A Certain Effect On Dogs And Can Help You Correct Their Behavior. The Dog Barking Control Device Adopts High-pitched Ultrasonic Design, Which Is Harmless To Pets And Humans. The Barking Prevention Device Can Be Used Indoors And Outdoors Because The Barking Control Device Is Ultrasonic, Which Means Humans Cant Hear The Stop Barking Dog Device, But Dogs Can! The Dog Bark Deterrent Gets Your Dogs Attention Without Causing Pain And Irritation. Safe:dog Barking Deterrent Is An Innovation In Barking Control Devices That Corrects Bad Behavior And Stops Dogs From Barking. It Is Effective On All Types And Sizes Of Dogs From 6 Months To 8 Years Ultrasonic Barking Control This Controller Uses The Latest Ultrasonic Technology To Silence The Dog And Avoid The Dog From Barking Too Loudly. It Is More Deterrent And Waterproof Than The Old Version. Material: Abs Colour: Black Package Con