It seems to work, sometimes it works and sometimes it doesn't, maybe it has to do with each dog's sensitivity to sound waves.

The battery compartment does not have the correct shape and size, resulting in pressure on the mechanism. Also, the terminals are farther apart and you have to bend the plastic to fit the 9V battery. I will not buy it again

It's a waste of money, it does nothing, it doesn't repel anything. I used it for a week, it doesn't deter any animals, the dogs almost tore me apart

It does nothing for dogs. I tried it on cats too, but only one cat moved away a little, but I'm not sure if it moved away because of the device. Clearly wasted money

I tried it on about 20 dogs, of which only 3 did not respond. The rest ran away!

It performs as it should! Tested both on city dogs and on dogs outside (strays, shepherd dogs) due to involvement with running and cycling. The effectiveness is noticeable at 15-10 meters! And always a backup battery in the bag as well.

In my case, either the dogs are deaf or the product does nothing... one lifted its ear a little, the others didn't even react...

Quite good.... It works on most dogs... Some literally ran with their tail between their legs, some stop barking and look sideways and strangely, and fortunately only a few did not react..... I don't know how it will work in a pack of strays... I say this because unfortunately they are increasing here and there... We probably need to hold 3 in each hand

Unfortunately, it did not seem useful to me. Obviously, it needs a lot of close contact to affect the animal. It does not work from a distance of 6-7 meters! You hear a sound and a light comes on.

Ok, I don't know if it does its job, I didn't need to get so close with dogs to try it...

It does not have the same result on all dogs, some are indifferent and on some it is annoying and they leave.

Every time I used it, I got a headache, whereas the dog is completely indifferent. It did not work on our dog.

I work as food delivery in a rural area outside Athens,Greece.
It worked with aggressive strays twice.
One group was 3 dogs,one was two dogs.
The best was with those 3 dogs.
I stopped to check my GPS,they smelled the food and started coming towards me barking.
Moment of truth.
I pointed at them directly with the laser pointer, they stopped barking immediately and started looking at each other confused.
They backed off slowly and slowly again disappeared in a nearby alley.
Satisfactory performance of the gadget.
I was expecting faster results(to see them run),but result was satisfactory.
They walked away and disappeared within one minute of constantly aiming at them.
It's ok for my job.
Definitely recommended.
Didn't work with wild domestic dogs, maybe they were trained before against this sound.
But I need it for strays so it's ok.
It worked with strays all the time.

Although I was considering getting it, half of you were saying negative comments and the other half positive. Finally, I bought it and I want to tell you that the product is incredible, but it needs to be close and it doesn't work on all dogs. As soon as they hear it, they get scared and some even back off. Some have paid 50 euros for such a product when it does a great job for only 10 euros. It does its job well

It works, but not as 'well' as I would like... In the same dog, it has a different reaction every time..!

I got the device for repellent and it does its job just fine. It doesn't have the same response on all dogs as some no longer listen while others have higher tolerance to these specific frequencies

I have exactly two dogs in a yard across from me that bark at anything and everything. As soon as I press the button, one of them runs inside the house and the other doesn't understand anything and continues unabated.
Same distance, marking, etc., so it purely depends on the breed of the dog and/or its character.
So it's worth the risk given the cost, and good luck to you!

The product works in most cases. First of all, its sound is perceived by all dogs. The reaction varies. Some get annoyed and run away, some stand and look with curiosity, some continue barking while keeping their distance. An important prerequisite is the immediate placement of a new battery from a reputable company. The one that comes with it does not work satisfactorily. Also, the distance of the tool from the dog and the direction we aim at play a big role.

For this specific repellent, I have to say that. The dogs are deaf or the repellent doesn't work.
When I press the button, the light turns on but it doesn't do the job for which I ordered it

I tried it and indeed it repels dogs as long as you aim at them for a few seconds. It doesn't harm animals, it just drives them away.

Useless thing, it doesn't work even inside the dog's ear, and even though it has the code ZF-853. They advertise it with prices ranging from €5.70 to 20 Euros, claiming it's reinforced as the price goes up

I bought it even though I had seen a negative review from others who had purchased it and said that the product does not repel dogs.
Indeed, I tried it on many dogs and it does nothing. They simply stayed where they were from the beginning.
I also tried it on aggressive dogs on the street and the result was that they continued their attack.
The only thing it does is to be used as a flashlight.