So far this product is great! The vibration is strong and so is the shock (my fiancé tried it on himself, not the dog) my dog is very responsive with this collar when needed. And I love how you can use it on multiple collars and switch the training to which collar you want to use. The only thing about this i don’t like is how the collar doesn’t stay where I set it to fit, it slides from where it was set but it’s not something that can’t be fixed.