The 5 oz Breastflow bottle is ideal for newborns and young infants and includes a Stage 1, slow flow nipple. Breastflow is the only feeding system that requires both suction and compression, just like breast feeding. The nipple is designed to mimic the breast so baby can latch on and to encourage the same mouth and tongue position as breast feeding. The double nipple system requires both suction and compression, just like breast feeding and baby controls the flow of milk. It's the bottle most like breastfeeding.