Basically the Pet Gentle™ is a device to help dogs and cats get rid of bad behaviors by playing a super high pitched whistle sound that only they can hear.
It doesn't hurt them at all but it will get them to stop their behavior.
What you'll want to do is wait for the behavior you want to stop, like: begging for food, non-stop barking at the door bell, barking late at night, destroying your couch cushions, or whatever annoying behavior needs to stop.
When your dog starts doing the bad behavior, physically get in between them and whatever they're doing wrong (couch, door, stranger, etc.) point the PetGentle™ at them and hold the button.
It will start playing a whistle sound that will get them to back away from it.
After that just let go of the button and give your dog some kind of reward (treat, head scratches, etc.) so they remember good things happen when they aren't being bad.
If your dog is being extra aggressive or tough, theirs also a flashlight on it you can point at them that will make it even more affective.
Plus, you can use the flashlight if you go on any late night walks.
On top of that, if there's someone else dog that is being aggresive towards you, you can use it to keep them away.