Both the 母乳実感® and the weak-suckling nipples can be attached. Made of heat-resistant glass that is easy to clean. Set of 5 bottles Set of 5 spouts. *Not compatible with nipples for general-purpose baby bottles (cap type) I was helped when my son wasn't drinking much milk and I was worried. It comes out with little effort, so it's suitable for what's called "lying down nursing." I bought it because I wanted the same ones as the hospital used. It's convenient because there are few parts to wash and sterilize.