Review on 🐕 Flexzion Ultrasonic Dog Bark Control Outdoor Pet Anti Bark Deterrent Device with Bird House Box Design - Waterproof, Battery Operated, Ideal for Home Garden Hanging by Ryan Hampton

The mic in this thing will only pick up barks when dogs are 5 to 8 feet away. Not even close to 50 feet. When it was just a small dog (5-8 pounds) barking once within 5 feet, it worked and the dog responded. So I confirmed that the dog is not deaf. A large dog of around 40-50 pounds just barked at him and didn't react at all. This device just isn't powerful enough to handle something big. The only thing I could use this for is a small dog in the room. 2 stars because it could be useful for that, but I don't think it lives up to its claims. Anything larger will likely require a custom solution. It doesn't look like any of the standard deterrents on Revain are strong enough.