100% Safe Anti Bark Device - Ultrasonic frequency is harmless to pets and has no effect on human ears. Humane sonic bark deterrents and a professional way to train your dog to stop barking with this house device for barking dogs. Durable &Weatherproof - Ultrasonic anti-smashing, durable, weatherproof, sturdy bark box bark control, lightweight, waterproof material, that can withstand any weather conditions . Excellent outdoor barking control. 33-FT Effective Range - Outdoor Bark Control is automatically activated when it detects barks up to 33 feet away. Can be hung on a tree, indoor, outdoor wall, or fence post to stop dogs from barking. USB Rechargeable - This rechargeable bark controller with indicator lights can be used effortlessly. A 5-hour charge gives you 30 days of use, saving you endless hassle and battery investment. No need to install batteries, it works right out of the box. (It is recommended to fully charge before use, the effect will be better) Adjustable Ultrasonic Level Control - Suitable for small medium large dogs! Emits harmless and effective sound to control excessive barking, but some dogs may be afraid or dislike the sonic sound, and not stop barking at the beginning, so please allow up to 2 weeks for training.