?Rechargeable-IPX4 Waterproof?- This bark control unit is equipped with a USB data cable, fully charged for about 5 hours, and can be used continuously for up to 5-7 days. And with a working indicator light, you can easily check the working status of the battery. When the 3rd gear is working, the indicator light on the anti-bark device flashes blue every 6s; when the dog barks triggers the anti-bark device, the red light stays on for 3s; when the battery is low, the red light flashes. ?Multiple Hanging Hole Design?- There is a small rotatable hook at the top and rear of this bark suppressor, which can be hung on trees, walls or fences; there are 2 holes embedded in the rear of the body, equipped with a punching device, easy Install. ?How to use?- This rechargeable bark control device with indicator lights is effortless to use. When working on 3 different levels, the light will flash blue every 6 seconds; when the bark deterrent is triggered by barking, the red light will be on for 3s; when the battery is low, the red light will flash. 3.7v 1500mah rechargeable battery can work for 15 days in 5 hours fully charged.Tips:It can take 2 weeks to work(Before that, it takes time to train your dog with the equipment.). ?Works for all size dogs ?- this bark control device has 3 different levels of ultrasonic waves, 15khz for large naughty dogs. 20khz acts on docile dogs. 30khz is friendly to small dogs. You can choose the appropriate mode according to the specific situation of your dog to achieve the best effect. (not suitable for hearing impaired dogs and will not work on two or more dogs at the same time.). ?Safe and harmless?- 33 feet (10 meters) wide control range; no irritating spray gas, no electric shock, barking stop device sensor only works when it catches barking. Safe for pets and harmless to humans, the bark stopper will automatically emit ultrasonic waves to stop dogs from barking.(33ft refers to the barrier-free space. If there are obstacles, the effective distance will be shortened~).