As a second time mom, these bottles are my absolute favorite! These stopped Cru from coughing, chocking, and no leaking out of the mouth. We’ve tried almost every bottle out there and these seem to be the closest thing to an actual nipple for nursing moms. The silicon is so soft and flexible compared to other bottle nipples. This bottle is also glass which was a huge factor for us. We won’t ever go back to plastic bottles LTKBump LTKBaby LTKFamily