◯ Breastfeeding Consultation SS Size x 2 These nipples are for baby bottles and are designed to help babies smoothly transition to breastfeeding. They require the baby to suck firmly to get milk, allowing them to practice with a sensation similar to breastfeeding. Used for about a month. ◯ Breastfeeding Realization M Size x 1, L Size x 1 Used for about 2-3 months. I rotated between several bottle nipples. Recommended for outings, travel, and as spares! ※ As shown in the third photo, the tips will be flattened for shipping. Please understand this before purchasing. I washed and sterilized them after each use. For extra precaution, I will sterilize them again before shipping.