This is because they haven't realized that the discomfort caused by their own barking makes them bark louder. There needs to be an adaptation process. This product triggers the product to emit ultrasonic waves when the dog barks at a certain decibel level.
eBay
Safe & Gentle Ultrasonic Dog Barking Solution - Instant Calm, Highly Effective Deterrent for
Aliexpress UK
We will respond to you within 24 hours. Item is in fully working order. LAST 5 PICTURES ARE OF AN ACTUAL ITEM.
eBay
Adjustable Pet Dogs Training Whistle Pets Discipline Supplies Stop Barking Ultrasonic Sound Flute
Aliexpress UK
Human automatic anti-barking device for dogs: This bark control device with the latest dog bark sensor system can accurately detect dog barking, safe for pets and harmless to people. The barking deterrent device automatically emits the ultrasound to stop dog barking, perfect for keeping your dogs calm when you leave dogs alone, and creates a peace department for your families and neighbors. .
eBay
Adjustable Pet Dogs Training Whistle With Rope Stop Barking Ultrasonic Sound Flute Pets Discipline
Aliexpress UK
Features:-It can get the dog's attention and quickly correct their bad behaviors within 1 second, such as barking, digging, chewing, scratching, biting, etc.-It emits a fixed ultrasonic frequency of 25kHz, a flexible ultrasonic frequency within the range of 20~30kHz, and different frequencies have different effects on different dogs.-Equipped with a powerful LED flashlight for easy use, it ensures visibility and safety during nighttime activities.-Built-in 2000mAh rechargeable battery, 2 hours USB fast charging, that lasts for more than 60 days.-The compact design makes it more suitable for ordinary people to hold and easy to carry.Specifications:Colour: black&orangeSize: length 4.72 inchesMaterial: ABSBattery capacity: 2000mAhPackage Included:1x Ant.
eBay
YOUQU Ultrasonic Dog Anti Bark Device Rechargeable Automatic Dog Barking Stopper Outdoor High Power
Aliexpress UK
Ultrasonic frequencies are harmless to pets and have no effect on human ears. Prevent your beloved dog and neighbors' dogs from barking in a humane way! Different dogs may be sensitive to ultrasound waves of different frequency bands.
eBay
ROJECO Ultrasonic Dog Repeller Anti Barking Training Device USB Rechargeable High Power Dog Repeller
Aliexpress UK
1 x Bark Arrester. Item Type: Bark Deterrents. Training supplies: It can be used as a tool to train your pet and improve the bad behavior of dogs. Portable: It can be used as a portable tool to drive away dogs when they are mad outdoors, so as to protect their own safety.
eBay
New Ultrasonic Barking Stop Device, Dog Driving Device, Noise Prevention Training Device, Automatic
Aliexpress UK
####Human automatic anti-barking device for dogs: This bark control device with the latest dog bark sensor system can accurately detect dog barking, safe for pets and harmless to people. The barking deterrent device automatically emits the ultrasound to stop dog barking, perfect for keeping your dogs calm when you leave dogs alone, and creates a peace department for your families and neighbors. .
eBay
Mini Ultrasonic Dog Repeller Training Dog Stop Barking Smart Portable Outdoor Defense Dogs
Aliexpress UK
Used to prevent dog attacks, issue ultrasound to repel the dog or wild wolf. This product adopts double channel enhanced, double dog training, excitation drive dogs, liting function is one of the super ultrasonic.
eBay
Dog Repeller Ultrasonic Dog Trainer Anti Barking Training Device Rechargeable High Power Dog
Aliexpress UK