Comotomo Baby Bottles feature innovative and sensible design to most closely mimic natural breastfeeding. Naturally shaped, soft, silicone nipples are ideal for babies who have trouble transitioning from nursing to bottle feeding. Your little one will love to hold onto the skin like, soft and squeezable body that is like no other bottle in the world. And you will fall in love with the wide neck design for brushless, stress free, cleaning bliss. Comotomo bottles are equipped with truly innovative vents that are smartly designed to prevent colic, while completely eliminating annoying leaks. They are quite possibly the most thoughtful bottles ever made. 150ml/5 ounce bottles come with truly slow flow nipples (1 hole) designed for newborns up to 3 months. 250ml/8 ounce bottles come with medium flow nipples (2 holes) ideal for 3-6 months.