Not your ordinary nipple! Breastflow ‘s patented 2-in-1 nipple lets your baby control the flow of breast milk or formula as naturally as breastfeeding by using both suction and compression motions. Nipples are BPA Free and come in a convenient 2-pack. Perfect for Breast Milk and Formula .88% of moms surveyed in an independent in-home bottle feeding research study said their babies .Breastflow is the only feeding system that requires both suction and compression, just like breast /Soft outer nipple mimics the feel of the breast, allowing baby’s tongue to stay in the same.