Instruct: Classify Amazon reviews into positive or negative sentiment
Query: AWFUL!!!

This collar did not stop my dog from barking at all. I have used a variety of bark collars and all of them had some effect and most worked, but this collar did nothing. Also it says is is for dogs with neck sizes from 8-28". The main part of the collar is so huge that it wouldn't go around my dog's neck (about 11") without leaving huge gaps on the sides. It is the worst collar I have ever had.