They're safe for dogs 5-120 lbs, from 6 months to 8 years old. The ergonomic design fits nicely in your hand, while a carabiner lets you take this ultrasonic dog bark deterrent anywhere. It has sound and ultrasonic modes with a frequency of 25 kHz that's hard for humans to hear.
eBay
Working Principle : The ultrasonic dog repeller emits 25KHz waves (audible to dogs 15Hz-50KHz). 1 x Ultrasonic Dog Repeller. which don't harm but deter barking and aggressive dogs.Target Audience: Effective for large, fierce.
eBay
【AUTO ANTI BARK COLLARS FOR DOGS】The latest citronella spray dog bark collar intelligently stop dog’s barking and automatically spray to stop barking. When the dog wears it quietly, it will not accidentally trigger the collar to start and work, nor will it be accidentally triggered by the barking of other dogs. (NOTE: the product doesn't include citronella spray, please purchase it separately)【PET-SAFE & HUMANE CITRONELLA DOG COLLAR】Citronella bark collar uses safe and harmless citronella spray to stop excessive dog barking and correct misbehavior. Using harmless anti barking dog collars, stop the dog's barking effectivly, harmlessly & humanely without physical harm to your pet dog.【ADJUSTABLE SENSITIVITY & SPRAY VOLUME】.
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Stop barking principle: through the microphone to detect the dog barking and trigger a warning tone electric shock vibration and other modes. Retractable Dog Lead Extendable Training Dog Leash Tangle Free Pet Double Leads.
eBay
Working Principle : The ultrasonic dog repeller emits 25KHz waves (audible to dogs 15Hz-50KHz). 1 x Ultrasonic Dog Repeller. which don't harm but deter barking and aggressive dogs.Target Audience: Effective for large, fierce.
eBay
Working Principle: The ultrasonic dog repeller emits 25KHz waves (audible to dogs 15Hz-50KHz), which don't harm but deter barking and aggressive dogs. Powerful Range & Portable Design: Perfect for outdoor use—walking, jogging or cycling.
eBay
This anti-barking device is suitable for indoor and outdoor use and will keep aggressive dogs at a safe distance from you, as well as correcting their annoying, destructive and unsafe behaviours, and will also repel those aggressive dogs with the right guidance from their owners
eBay
Working Principle : The ultrasonic dog repeller emits 25KHz waves (audible to dogs 15Hz-50KHz). 1 x Ultrasonic Dog Repeller. which don't harm but deter barking and aggressive dogs.Target Audience: Effective for large, fierce.
eBay