Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Wet Baby

These bottles come with an extra plastic piece on the inside. Most bottles do, except with the other bottles the plastic piece is disposable packaging. Don't make the mistake of throwing it away when you purchase AVENT Bottles or else you'll end up with a wet baby from the leaking bottle. Why purchase these more expensive bottles when you have an extra piece that needs to be washed and kept up with in order for them to function properly? I don't get it! I recommend Nuk bottles as a better plastic alternative.