Effective For Dog Training- Which Uses The Principle Of Ultrasound To Emit Sound Waves To Interfere With The Dog, So That It Feels Stimulated And Stops The Current Behavior. Can Help Owners Control Nuisance Barking And Prevent Some Bad Behaviors Of Dogs, Such As Excessive Barking, Chasing, Feeding Or Fighting Etc. Suitable For Dogs Of Different Sizes (Except Dogs Under 6 Months And Aggressive Dogs).Adjustable Frequency Technology And 2 In 1- Ultrasonic Anti Barking The Side Button Has Three Different Sound Wave Modes. After A Long Period Of Adaptation, The Pet'S Hearing Will Lose Its Immunity To Certain Sounds, So Multiple Sound Waves Will Destroy The Dog'S Resistance To Certain Sound Waves. It Can Extend The Effective Use Time Of The Product, So That You Can Alternately Use Different Sound Waves Each Cycle.Safe For People And Dogs- The Ultrasonic Bark Control Device Uses The Latest Ultrasonic Technology, Le Uses A Frequency Of 22-25 Khz, Which Is Difficult For Human Ears To Perceive, The Sound Does Not Affect Humans, But It Is The Most Sensitive Frequency For Dogs, And The Sound Will Not Negatively Affect The Dog'S Hearing Or Health, It Can Easily Attract The Dog'S Attention And Prevent Bad Behavior.Portable, Usb Rechargeable- This Dog Anti Bark Device Comes With An Adjustable Wrist Strap And A Usb Cable For Charging. Which Is Very Suitable For Outdoor Walking And Training. The Ultrasonic Bark Control Device With A Built-In 300Ma Rechargeable Lithium-Ion Battery Can Last For 20 Days Without Worrying About Running Out Of Electricity.The Ultrasonic Dog Mosquito Repellent For Dogs Has A Working Distance Of 5 Meters And .Buy With Confidence- Anti-Bark Device Is Suitable For Both Indoors And Outdoors For Dog Walking. The Device Can Also Be Used To Train Dogs And Their Behavior. Let Them Live Well In Public Places And Protect Them From Eating Unhealthy Food. [Contact Us: If You Have Any Questions, Please Ask For Help Via Email Or Amazon Messenger Instead Of Giving Us A Low Score. ]