I love my Haakaa silicone breast pump! I have been using it for two weeks and I no longer have to use my electric pump. I breastfeed when I am home and with each feeding I use my Haakaa on the other breast. I collect 1-4 ounces of milk and that is what I save for my son when I go to work. He is now eight weeks and I truly believe my milk supply has grown by at least 15 ounces a day from pulling the milk from my other breast using the Haakaa. All new moms who plan to breastfeed and what a freezer stash without the hassle of using an electric pump should definitely give it a try. I do not think it can replace your pump if you are  exclusively pumping. Just in the past two days I have used it every other feeding and have collected 25 ounces of milk!