Instruct: Classify Amazon reviews into positive or negative sentiment
Query: I'm a little concerned

I know this product must work, I mean it worked fine for us, but my baby was born at 10 lbs. When I found out that it wasn't approved for my carseat though, I took it out. I think they should make specialty headrests for each seat, which some carseats do. I had a problem with the headrest for my carseat though, because it didn't support my first baby's head. That's why I bought this one.