I read several of the reviews here before purchasing this item. Like in other reviews, I also discovered that it has limited/no effect on small dogs. I have two miniature poodles and they both blasted out the door one morning making all kinds of noise. Though not at all why I bought this – I thought it a good opportunity for a gentle testing. I quickly/just briefly touched the button with no response from them, indicating that they heard it at all. As I also cannot hear it – I was wondering if the device even worked. A few days later I came across the same large wild dog while riding my bike, that caused me to purchase this item in the first place. I touch the button and he seemed to hear it – and he headed in the other direction quickly. To be honest though, I was still lacking confidence in how effective this really was. This past weekend I had this device with me, while on an outing (I am working overseas). A troop of wild baboons came upon us like a wave. It was actually quite disconcerting. They were closing quickly and starting to flank us on both sides. I had a walking stick and could keep one of them back at a time, by simply pointing the stick at them. But given there were 35 to 40 of them – obviously this was not going to work. Not knowing whether this device would work on baboons of course – I pulled it out and presed the button. I can now say with absolute confidence that this device works exceptionally well. With the button depressed – I waved it at the front line of advancing baboons and not only did it stop them dead in their tracks – it repelled them. They did not act like it hurt them – but as stated in other reviews – it was definitely not a noise that they liked or understood… which gave them a moment to pause and made them back up. They were not intent on hurting us – rather just interested in getting some food. The problem is they all wanted that and were intent on that happening – and happening immediately. It could have resulted in a frenzy and trouble for all of us in a hurry. This device allowed me to keep them at bay long enough for the rest of our group to dig out some food for them and distribute it without incident. That was the end of the anxiety for all involved. This “Dazzer” is brilliant. It very likely prevented us from having serious problems and it very certainly prevented me from having to take more drastic measures to protect us. I am very grateful for both… and all involved had a pleasant experience as a result.