Powerful and rechargeable Our ultrasonic anti-bark stopper has an effective range of 15 m. There are 4 sensitivity levels and 3 ultrasonic frequency levels. It only takes 2-3 hours to fully charge the built-in lithium battery, and it can be used continuously for up to 30 days. Safe and humaneUltrasonic frequency is harmless to pets and inaudible to human ears. The Sonic Solutions Anti-Barking Deterrent is a perfectly safe and effective training tool to stop your dog or your neighbor's dog from barking. Intelligent automatic frequency Automatically emits the 4th ultrasonic frequency, switches from the 1st ultrasonic frequency to the 3rd ultrasonic frequency, prevents barking dogs from adapting to the same frequency for a long time. Easy to install and waterproof Hang or mount our ultrasonic anti-bark device for dogs on a tree, wall or fence post to stop your or your neighbor's dog from barking. Make sure the ultrasonic bark is for dogs without obstacles within range.