Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Excellent little pump

I LOVE the Isis pump. It is quiet, and reliable. I used it with my third child, as I needed to keep working full time, and there were no outlets in the room I had to use, so the hospital pump was only useful at home. I was able to pump 9 - 10 oz in 15 minutes. The flexible "Petal" insert really stimulates the let down. It is sturdy, but sometimes the milk DOES back up if you don't let up on it for a moment to let it back down. If you get too eager, sometimes the top and pump lever will pop off (does NOT lose any milk though). I DO hope that Avent will improve some of those things, like the petal insert and travel cover falling off. Another reason I only gave it a four star, is that there are no other flanges for larger size nipples, and the petal insert is so tight on mine, I had to pry it off. That won't be problem for most women though, and I plan to use it with this baby too, only I guess I'll have to leave out the petal insert.