I bought one of these on the recommendation from a friend who claimed this worked just as well as her hospital-grade electric pump (I have since decided she is from another planet). When my milk first came in, I was able to get 4-5 ounces in 15 minutes. But after a few weeks, I was having to pump for 30 minutes to get 2 ounces, leaving my breasts bruised and sore. I finally rented a hospital grade pump and learned these are the greatest inventions ever. I actually tried my hand pump again a few weeks ago to see how it would work if I ever needed to pump away from home and I uncomfortably got half an ounce. I then went to the electric pump and got 5 ounces. Buy this only if you are extremely engorged and need to pump occasionally for relief, but not if you plan on pumping daily. You will waste precious time pumping when you could be sleeping.