These leak! I used to use these bags 7 years ago with my first child, and these were great, so I got them again for my second. But they must have changed the product! Half the time, these bags leak and my breastmilk is all over the place! I simply cannot use these. They leak when I thaw them (in warm water, or in the refrigerator for one day). Literally have only thawed maybe 10-12 bags and 5 or so have leaked. Returning!