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

These containers stink! Yeah it is great, I can use them with the wonderful ISIS pump, but I DON'T HAVE A CHOICE. You HAVE to use these with the isis pump unless you have a conversion kit, and they leak. Terrible. I have used this as a container for my precious pumped milk, went to open it and milk somehow gets locked in the grooves and just drips out. Also, I have used this as a bottle and milk leaks out no matter how tight.The pump is great, the containers stink.