For the mothers that need milk storage bags, you hear the name Medlela and think you are getting what you are paying for (which is pricy) Well on this case, I am going to tell any mother that pump and need milk storage bags, do not throw away your hard earned money on these ones. They hold 5 ounces. That is it. There is many bags out there that are labeled to hold 6 ounces that I have been able to pour at least 10 to 15 ounces into a bag. Furthermore, these bag do not like to seal right. Yes, they do come with this nifty little tool that allows you to pump right into the bag without having to use a bottle. I found it more of a hassle than a bottle. I can pump out a good 6 to 7 ounces a side, and these bags fit 5? I would have to stop in the middle of a pump just to change the bag. I don't want that hassle. I would rather have my 10 ounce bottle that I empty in between pumps then have to stop monkey around with a very hard to seal bag, rehang a bag, and start pumping again. No thanks! Save your money mom's, buy cheaper! This time it will pay off on skipping out and buying cheaper breast milk stuff.