1.Upgraded Dog Barking Control Devices- Adopting the latest ultrasonic technology; the dog barking control devices will automatically emit high-pitched tones that only dogs can hear. Automatically sense the dog's sound; once the dog stops barking; the ultrasonic barking controller will automatically stop emitting ultrasonic waves. The ultrasound emitted by the anti barking device will correct the dog's barkin.2.Safe for Dogs and People- The anti barking device is safe and effective for dogs of all types and sizes (10-130 lbs). For dogs 6 months to 8 years old. Most humane and used widely way to keep your own dog or your neighbors dog from barking.3.4 Levels of Barking Control Devices-  The barking control device with four adjustable ultrasonic volume levels - test; low; medium; and high; Please turn the knob to test different frequency bands for best results. The range of ultrasonic penetration is 50ft (If placed indoors; should the sensitivity be adjusted to 1). If the dog is hard of hearing or aggressive; the device may not work as intended.4.Waterproof & Durable No Bark Control Devices- Sonic bark deterrents dog silencer come with a well-designed cute shape. Hang the dog bark control in a tree; on a fence post or anywhere. ur anti barking device can work even on windy and rainy days.5.User Guide & Sincere Service- No bark bird box for dogs - Operates 9-Volt batteries and will last up to 1 months depending on use. stop barking works best with the anti barking device. Please know that the battery is not included in the box. If you encounter any obstacles in the process of use; or the anti-barking effect is not satisfactory; please be sure to contact us; we will be happy to help you solve the problem.