Dr. Brown’s preemie flow nipple is our slowest-flow nipple, great for preemie and breastfed babies. Dr. Brown’s uniquely designed preemie flow nipple works together with our internal vent system to help babies feed at a pace that’s perfect for them. Each preemie flow nipple offers the same consistent flow, so both you and baby know exactly what to expect. Made of super-soft, high-grade silicone, these preemie flow nipples fit all of Dr. Brown’s standard/narrow bottles. Dishwasher (top rack) and sterilizer safe. BPA free.