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

I couldn't figure out why the heads kept breaking off the brushes. I've had this happen 4 times in the past 6 months (1 brush at work, 1 brush at home). Then I decided that perhaps they were counterfeit, not knowing at the time about the thriving market for counterfeit Oral B brushes. Looking closely at the broken off brush head, two of the 4 long yellow things (flossers?) are also broken off.I will never buy brushes on Amazon again.They are much cheaper for a reason ...