Instruct: Classify Amazon reviews into positive or negative sentiment
Query: convenient, but...

I had gotten these bags to use with a rented Medela Lactina while my preemie was in the hospital. If you are pumping for a NICU baby, nurses do not like to handle the bags to transfer the milk into the volu-feeders/small hospital bottles (if you're lucky enough even to be in a breastfeeding-friendly hospital). Nurses are still handling a bodily fluid and it's extra steps for them if you're not the one handling all of the feedings. Also, the bags do not stand up on their own, which is frustrating if you're truly pumping straight into the bag. Like other reviewers, I found that the top tab tore poorly also. They are good for fast backup if you have no other sterile reusable milk storage container, but I ended up using theMedela Breastmilk Freezing & Storage (*BPA Free) 12 Pack of 80ml Bottles in Retail Packaging #87061long-term and was very happy with them.