These are two size S nipples from the Pigeon Mother's Milk実感 series that I bought a while ago. I didn't use them at the time, but I used them this time for my baby! I was breastfeeding, but I had severe mastitis and my milk ducts got blocked, so I wasn't producing enough breast milk. I supplemented with formula, so I used these nipples. I used them for about two weeks, until my incision healed. Instant purchase is welcome! Please ask any questions in the comments!