We purchased this nipple because it's slow flow and sold by enfamil store. I rarely give bad reviews, but I have to say this nipple has bad quality. My little one sucks it and the nipple changed the shape while she is sucking. It took her a lot of efforts. Then leaking from her month or we had to pull it out. We tried 4,5 nipples. Most of them are not good then we never use the rest. Not recommended it looks different from what we purchased years ago.