I have the Spectra S1 pump so decided to get these storage bags, have not had any problems with them apart from the measurements as I hadn’t realised they were US measurements.
We tried another brand once these had run out but regretted getting them as they started to leak as the seal was tough to close, we never had any problems with the Spectra bags!
This bags are nice and simple to use, makes storage easy. It could be user error but I used these bags and the amount it appears is in the bag is very different when poured into a bottle. Not easy to open the bag properly when you can't put your hand inside to ensure base is flat. If you're filling it with a lot of milk this may not be an issue but with less milk the weight isn't there to open fully so difficult to measure.
These Spectra 'Pre-Sterilsed Disposable Milk Storage Bags' ( 30pcs ) are very simple to connect to the breast pump. They are coated and treated specially to block out air and moisture, keeping the expressed milk fresh.
The bags can be sealed shut to prevent any contamination or leakage. The scale on the front of the bags lets you to see how much milk has been expressed. The pre-sterilized bags are double-walled and are freezer safe.
Please note that the date printed on these bags is the date of manufacture. These bags do not expire.